As the US voted on Super Tuesday, Al Jazeera examines how the race unfolded.
All times are in GMT:
Romney is projected to take Republican victory in Alaska, according to Reuters news agency.
Obama is projected to win Democratic vote in Alaska, NBC reports.
Mitt Romney is projected winner of Republican vote in Colorado, according to AP. Barack Obama projected to take Democratic vote in Missouri, CBS reports.
Barack Obama is projected winner in Utah's Democratic primary, NBC reports.
Clinton takes Democratic victory in Missouri Democratic contest, according to Reuters.
0515 GMT, Veronica Pedrosa, Al Jazeera, Los Angeles, California
We've just heard that a judge in a county near San Francisco has ordered that 14 polling stations must remain open because they ran out of ballots, apparently.
While voters are still there wanting to vote, the judge is saying those precincts must stay open.
It speaks to the sheer number of voters wanting to make their voices heard here in California.
Hillary Clinton is projected Democratic winner of California, while McCain is projected winner for Republicans in that same state, NBC reports.
Clinton is projected winner of Arizona, according to AP, while NBC reports that Romney is the projected Republican winner in Montana.
|Romney's bid for California is|
key to his candidacy [AFP]
McCain projected winner of Republican contest in Missouri, according to AP news agency.
Barack Obama is projected winner in Democratic primary in Colorado, according to NBC. Romney is projected the winner for the Republican contest there, according to CBS.
Obama gives speech in Chicago, Illinois after projected win in Illinois.
"Our time is now, our movement is real and change is coming to America," he says.
Mike Huckabee is projected winner of Republican contest in Tennessee, according to AP news agency. McCain wins Republican primary in Arizona.
0435 GMT, Veronica Pedrosa, Al Jazeera, Los Angeles, California
In the Democratic contest, with one per cent of the votes counted, we are hearing that Hillary Clinton is in the 50s in percentage terms. Obama is in the 30s, in percentage terms.
In the Republican primary here in California with two per cent of votes counted, we are hearing that McCain has won 60,000 votes and Mitt Romney 30,000 votes.
This is very early, but of course everyone here is talking about California being the big prize because there are so many delegates up for grabs here.
This contest is Romney's last best hope. If he wins here it could sustain his campaign.
Romney is projected winner of Republican caucuses in Montana and Minnesota, according to AP news agency.
0420 GMT, Dave Marash, Al Jazeera, Washington DC
I think that McCain has done well tonight but perhaps not well enough to put a stranglehold on the nomination.
He will be the majority candidate [but] he will not I think have the controlling number of delegates unless he unexpectedly wins in California.
|Obama said in Illinois that he|
was aiming for change [AFP]
California was the one state where Romney actually spent some money. One of the things we heard tonight was Mitt Romney and Mike Huckabee saying that the campaign is going to go on – it is going to be a three person race.
The question where Romney is concerned is: will he put his money where his mouth is?
Until this last week with the buy in California of about $2m worth of advertising, he had not been spending much on Super Tuesday, because frankly his expectations were low.
Hillary Clinton is projected winner of Arizona state Democratic contest, according to NBC. Barack Obama is projected winner of Idaho.
0405 GMT, Veronica Pedrosa, Al Jazeera, Los Angeles, California
Everybody knew that California's race was going to be very close. The second place candidates up until very recently, Barack Obama and Mitt Romney, have come up from behind with very strong challenges to frontrunners McCain and Clinton in the closing days.
In the last 24 hours, Obama and Clinton have launched intensive state-wide efforts…. to get the vote out. Whoever comes second here in the Democratic contest is still going to claim a substantial number of delegate votes.
The race in the both Republican and Democratic contests in California is too close to call.
Hillary Clinton gives speech in New York, where she is a senator, saying that her campaign will go on for every oppressed person in the USA.
|Clinton gave a rousing speech |
in New York [AFP]
Mitt Romney gives a defiant speech in Massachusetts, saying his campaign will go on despite heavy losses to John McCain in Super Tuesday.
0300 GMT, Dave Marash, Al Jazeera, Washington DC
The story of the night is that Clinton has done better than she thought she would in the northern states.
She has also been "holding her serve" - keeping white and female votes and
holding the mid-South, while Obama has held the deep South where there are many black voters.
Meanwhile Huckabee has caused a great deal of consternation on the conservative side by blocking Mitt Romney.
For Romney now it depends on how well he does in California, where in polls before the vote he had a narrow lead, to see what happens.
0245 GMT: Max Blumenthal, blogger, New York, US
It seems Huckabee has been the spoiler of Mitt Romney and has thrown the election to John McCain.
I think Huckabee is making a play to be McCain's vice-presidential nomination. McCain is despised by the Christian right, by people who like to hunt with rifles and people like the right-wing talk show host Rush Limbaugh, who has said he'd rather vote for a Democrat than McCain.
So I think McCain needs Huckabee and so Huckabee is staying in the race to destroy Mitt Romney.
I have personally spoken to evangelical voters who believe he is a cult member because he is a Mormon, but also I think people dislike his character.
0235 GMT, James Bays, Al Jazeera, New Jersey, US
A huge cheer went up when it was finally announced that Clinton was the winner in New Jersey, it had been too close to call.
But the fact it may have been so close will be a little worrying for some in the Clinton camp.
0230 GMT, Dave Marash, Al Jazeera, Washington DC
Both Massachusetts and New Jersey are important victories for Clinton - over the past week New Jersey had shown Obama all but catching up and it looks like she will stand clear by several percentage points.
It's very interesting in Massachusetts, Obama had the endorsement of the governor but he also had the majority of Kennedys, what this may point to is that voters thought this is an election about change and they don't care about endorsements.
|Huckabee held his own|
in Alabama [AFP]
On Huckabee, in terms of presidential politics he is not significant as he is not likely to be the vice presidential candidate.
What he has done is to throw a spike across the tracks of the Romney campaign and killed him tonight, frankly.
0215 GMT, Rob Reynolds, Al Jazeera, Washington DC
I'm seeing a lot of disparate trends where people concerned on the economy are voting for Clinton and McCain, while young white and black voters are voting for Obama.
I think that with Romney, Huckabee had a good quip in Iowa where he said that most Americans would rather vote for the guy who works beside them than the guy who laid them off.
There may be something too that; Romney maybe reminds them of their boss or the ruthless side of capitalism.
New Jersey will be a blow to Obama, he had campaigned heavily there in recent days.
Also regarding Alabama [going to Obama] it's not a surprise, Obama will be happy but states like Alabama and Mississippi do not tend to vote Democrat, so the nomination is one thing, a presidential win is another.
I think McCain has been pointing to Clinton as the one the Republicans are running against. If you look at polling data she doesn't always do so well against Republican challengers, so I think they would like to see her as the nominee as this would galvanise their hardcore supporters.
Hillary Clinton projected to win the Democratic race in the eastern state of Massachusetts, based on exit polls.
Hillary Clinton wins the Democratic presidential primary in the crucial state of New York, NBC reports citing exit polls, where she is in her second term as senator.
Mike Huckabee is the projected winner of the southern state of Alabama's Republican presidential primary, according to reports.
Projected results for Arkansas Republican primary show Mike Huckabee, the state's former governor, as winner, NBC reports, while the north-eastern state of Delaware is reported to go to John McCain in Republican primary, based on exit polls.
0120 GMT, John Nichols, political writer for The Nation, Washington DC
It's intriguing that the South really seems to coming through for Mike Huckabee. Huckabee is doing better than expected, and that is very bad for Mitt Romney.
0115 GMT, Pat Schroeder, former US Congresswoman, Washington DC
They always say that Democrats fall in love and Republicans fall in line. [about Clinton and Obama becoming running mates] - Well you never know, it depends on what they really feel by the time they get to Colorado - where the Democratic convention is held.
Meanwhile, if McCain wraps it up tonight and the Democrats don't, he's going to have this wonderful honeymoon period. No more debates and plenty of time to fund raise.
NBC projects that Hillary Clinton has won the Democratic presidential primary in Tennessee, based on exit polls.
0105 GMT John Nichols, political writer for The Nation, Washington DC
You're starting to see a real northeast sweep for McCain.
If you lose your home state, you're in trouble, but if you lose your region, well Mitt Romney is a media star in New England.
Mike Huckabee just needs a plane ticket to keep running, anywhere he goes there's always an evangelical church he can go to or a crowd he can talk to.
Obama projected to win the Illinois Democratic primary, based on exit polls. John McCain projected to win New Jersey, Connecticut and Illinois Republican races. Romney projected to win Republican race in Massachusetts, where he was formerly governor. Hillary Clinton projected to win Oklahoma's Democratic primary.
0055 GMT, John Nichols, political writer for The Nation, Washington DC
The Obama campaign spent $2.5 million on a single ad in the Superbowl [US football game] and it was a powerful ad. We may see if it makes a difference.
Campaign-wise the fact is all campaign nastiness has now moved to radio and the mail. If you get too nasty on televison we can see it, but through the mail it is hard to catch.
As for Caroline Kennedy's endorsement of Obama, this is a unique circumstance. Obama is an untested figure and we knew little about him, but in the Democratic party there are two dynasties - the Clintons and a greater, deeper Kennedy dynasty, and the fact they have gone for Obama makes it another dynastic battle.
Reports from NBC that John McCain has won the Georgia Republican presidential primary, citing exit polls.
0015 GMT, Rob Reynolds, Al Jazeera, Washington DC
If confirmed, Obama's win in Georgia would not be a surprise, there is a big African-American population in Georgia, as there is in Alabama and Tennessee.
As for the Republicans in Georgia we're hearing the race may be too close to call, which is interesting. It has a large evangelical base and they may be going for Huckabee, hence splitting the vote if Huckabee can scramble up the polls a bit more.
By far the nastiest race is the Republican one, especially between McCain and Romney. This morning McCain received an endorsement from Bob Dole, the former Republican presidential candidate, and Romney said Bob would be the last person he'd want an endorsement from.
What he meant was that Dole represented the old guard, but McCain seized on it and turned it on Romney to make out he had attacked Dole - a decorated World War II hero.
So McCain did not hesitate to make out as though Romney had slurred someone's record.
0005 GMT, Hady Amr, Brookings Institution, Doha, Qatar
I think both of those candidates [Clinton and Obama] are committed to withdrawal.
The central tenet of Obama's campaign is the concept of joint security, our approach will be dialogue. Obama believes that you make a difference by speaking to people, not by hiding from people.
Going into the presidency, a candidate will say: "These are our objectives, but along the way, you have to take detours to those objectives."
0005 GMT, Seyed Mohammad Marandi, political analyst at Tehran University, Doha, Qatar
Iraninans are sceptical [of the presidential race]. They don't believe there's a huge difference between the candidates, but the Democrats are bit closer.
Iran is looking for a person who's willing to take an new look at the region.
AP news agency reports that, with polls closed in Georgia, Democratic candidate Barack Obama has won the southern state's Democratic primary.
2345 GMT, Kimberly Halkett, Al Jazeera, Phoenix, Arizona
This is McCain's home state and he is expect to take it by a wide margin. He is expected in the state in a few hours time.
Earlier McCain spent the morning campaigning in New York City, then he headed to San Diego to campaign and get that last push before the polls close.
There is serious acrimony between McCain and Romney, with accusations that McCain is too liberal for a Republican and not close enough to the core values of the Republican party.
McCain in turn has fought back with an expensive commercial - called "Trust" - emphasising himself as a trustworthy candidate.
We see in the national polls now that McCain has a lead, but he says he is a superstitious man and will not take anything for granted.
2315 GMT Ghida Fakry, Chicago, Illinois
Obama went with his wife Michelle to cast his vote in Illinois. He has been keen to lower expectations even though he has enjoyed a surge across the nation.
Last night his campaign manager said in an email sent around that if he comes within 100 delegates of Clinton he would be in "good shape" but he could do even better than that.
Clinton was of course born in Illinois and went to high school here, but there is a sense of excitement over Obama.
We spoke to young voters and they say they are voting for Obama as they feel he can make a difference. There is also the likeability factor - some feel she is too polarising a candidate and that Obama would be a much tougher candidate for the Republicans to beat.
2305 GMT, Rob Reynolds, Al Jazeera, Washington DC
West Virginia's caucus win for Mike Huckabee is a deceptive result, as most of McCain's caucus goers went over to him to deny Romney a victory in a strategic vote.
AP news agency reports that a record turnout is expected for the Super Tuesday vote.
Also, eight precincts in Chicago were said by AP to have experienced minor problems with voting equipment and a ninth was delayed in opening.
2115 GMT Josh Rushing, Al Jazeera, Times Square, New York
The economy is the lead issue here. New York City is the economic capital of America so here the war in Iraq has fallen second to the economy.
I'm in Times Square, what many people refer to as the the house that Rudy Giuliani built. Before he dropped out he used it in his campaign as a sign of his leadership - how he made it a safe place.
Many New Yorkers I spoke to said they would have voted for him if he was still in race, but as it stands they are going for McCain.
2100 GMT Dave Marash, Al Jazeera, White House, Washington DC
It’s the most interesting and the most unpredictable Super Tuesday in recent US political history.
On the Democrat side, here you have Hillary Clinton, like the girl in the movie melodrama tied to the tracks and the locomotive of momentum - called Barack Obama. Will Super Tuesday snatch her out of danger before the momentum of Obama crosses the line and makes him a winner?
Party professionals in both camps are disclaiming any likely victory tonight. In fact surprise is the the only predicable element of this race so far.
On the Republican side in all likelihood things will be perfectly clear. McCain has firmly established himself as front runner and by the end of tonight's balloting he should have a substantial lead.
Romney has made up no ground, even in California where he is likely to get a large share of delegates.
McCain's hand is very strong.
1925 GMT: West Virginia
Mike Huckabee wins the caucus race for the Republican nomination in West Virginia with 52 per cent of the vote - and 18 delegates - according to US media projections.
1810 GMT: Lucia Newman – Los Angeles, California
California is the largest, the sweetest dish in this race. It's like the dessert.
There are 370 delegates for the Democrats, 170 for the Republicans - about 300 per cent more delgates than in some of the smaller states. So everyone will be waiting until the last moment to determine who the winner of this California race will be.
|McCain began super Tuesday |
with a lead over his rivals [AFP]
The Hispanic vote is crucial, especially this year. A lot of the Spanish language stations, here in Los Angeles for example, have been calling on Latinos to come out and make their voices heard, especially in a year where immigration has been such a big issue.
Most say they will vote for the Democrats and specifically Hillary Clinton - because of the softer, more gentle administration of Bill Clinton.
The Arizona for Hillary campaign reports of "irregularities" which have included "registered voters' names not being on the registration lists, identification problems, changes in polling place locations voters have not been notified of, and voters who were not provided the opportunity to vote by provisional ballots," in a press release.
1800 GMT: 1700 GMT: James Bays - Manhattan, New York City
We've seen Barack Obama supporters on the streets of Manhattan, trying to get their voice out - I've spoken privately to them and they say they don't expect to win here, the home state of Hillary Clinton.
They think they are, though, narrowing her lead. Some Barack Obama supporters have said that he'd have hoped it was Super Thursday rather than Super Tuesday. He seems to have the momentum, but not the time to beat her [Clinton], certainly here, in New York.
1730 GMT: Virtual Poll latest
Al Jazeera's online virtual poll reveals that 54.7 per cent of people favour Barack Obama as the Democratic presidential nominee, and Ron Paul leads the Republican vote with 10.9 per cent.
Place your vote here!
Please note the results of this online poll are not scientific and are indicative only as a representation of the views of Al Jazeera's readers.
1700 GMT: James Bays - Manhattan, New York City
This is the most super Tuesday ever, because there are 24 states taking part in one day.
I can't promise that at the end of super Tuesday we'll have a clear Democratic or Republican nominee, but there'll certainly be a clearer picture.
1605 GMT: Lucia Newman – Los Angeles, California
The 'Golden State' is a gold mine for delegates. In Alaska and North Dakota there are 13 delegates at stake, but here there are 370 delegates at stake for both parties.
Who are the favourites? Right now McCain has a two digit lead according to two polls, so the big race is the Democrats, but it will be some time before outcome is clear.
1600 GMT: Rob Reynolds, Al Jazeera, Washington DC
This is a vast process – let us focus on New Jersey, an important state with many delegates and Clinton had been expected to do very well, but Obama has been campaigning very hard, was there yesterday with Senator Ted Kennedy and Rob de Niro. If he does very well, it will offset Clinton.
Meanwhile, in Massachusetts, Obama has obtained Kennedy’s endorsement. Clinton’s popular in Massachusetts, but on the Republican side, it's Mitt’s home state. If he doesn’t carry it, then he may as well pack up his campaign bags and go home.
Concerns have been raised over adverse weather conditions and how they could affect turn out in crucial Super Tuesday states, after heavy snow or rain fell on Tuesday morning in parts of Arkansas, Colorado, Connecticut, Illinois, Kansas, Massachusetts, Missouri, New Jersey, New York and Oklahoma.
1515 GMT: Nick Spicer, Al Jazeera, Selma, Alabama
We're here at memorial stadium, in Selma, Alabama - an iconic state for the civil rights movement.
People are turning up to vote in record numbers.
Alabama is a small state, but the lesson of this Super Tuesday is that, really, there are no small states – particularly for the Democrats and particularly for Obama.
What's happening here in Alabama is the same as nationwide for the Democrats. There has been a surge in support for Obama - he has gained eight points to now lead Clinton.
But this is not reflected in Alabama in the Republican race. Huckabee has a lot of support in these church-going states as he is against abortion and gay marriage, so generally he is in second place just behind McCain.
1505 GMT: Lucia Newman, Al Jazeera, Los Angeles, California
The polls here just opened a few minutes ago as we are on a different time zone. There is a very large turnout.
|Voting has begun in the western|
state of Arizona [GALLO/Getty]
Superlatives abound here - California is the largest state in the US with one in eight Americans living here. There are also 10 times as many delegates as in some of the smaller US states.
For the Republicans, McCain does have a comfortable lead here, but on the Democrat side Clinton and Obama are running neck and neck so no-one is making any predictions.
We cannot underestimate the Latino vote here - this morning on the Spanish language news channels they were urging those Mexicans and central Americans who can do so to cast their vote, saying it was time their voices be heard.
On the Democratic side, most say they will vote for Clinton, there is enormous support for her in this state.
1500 GMT: James Bays, Manhattan, New York City
Polls here opened four hours ago. I'm right by a polling station with a steady stream of voters arriving this morning.
New York is the second biggest prize in terms of delegates and very important for Clinton – this is her home town and the battle is already underway here.
At this station outside there is an Obama campaigner trying to get votes and Obama does seem to be narrowing her lead.
On the Republican side, McCain, crucially, is backed by Giuliani who pulled out earlier in the race.
This will give the Arizona senator key support.
1420 GMT: John Terret, Al Jazeera, Washington DC:
Americans are about to make electoral and political history, with both registered and unregistered voters in 24 states trying to chose nominees for both the Republican and Democratic candidates.
It is important for international viewers to realise what this is - basically it is about electing the next president of the US.
Whoever wins will have control over US foreign policy for the next four years and it is also crucial for the global economy - the US economy on the tipping point of recession and if it does in fact enter a recession, this could have a nasty knock-on effect across the world.
The candidates have been out and about on television. Clinton is the only candidate to vote so far, at a polling station about 35 miles north of New York City.
The Clintons voted north of New
York city early on Tuesday [AFP]
What is interesting on the Republican side is that there is a real split opening up in the Republican party – John McCain is likely to be the frontrunner but many in his party are unhappy with his voting record on issues such as immigration and tax.
Meanwhile, Mitt Romney has said that if the US wants a real conservative they should vote for him, not McCain.
1400 GMT: Hillary Clinton casts her vote in New York - the state she represents in the US senate - accompanied by her husband and former president, Bill, and her daughter Chelsea.
1100 GMT: Polls open in eastern states.