Tensions between Democratic presidential frontrunners Hillary Clinton and Bernie Sanders are intensifying.

At rallies and events around Charleston, South Carolina - where the fourth Democratic debate was held on Sunday night - supporters openly tried to outshout one another with their pledges of loyalty.

It was an indication of just how tight this competition has become.

Shortly after announcing her intention to run for president, Clinton appeared to be the inevitable Democratic presidential nominee with little competition.

Increasingly, though, this lead has slipped away, making 2016 look more and more like 2008, when Clinton lost the nomination to a then relatively unknown US senator, Barack Obama.

Clinton and her supporters are working hard to make sure that doesn't happen again. As Clinton has watched her lead narrow in Iowa and disappear in New Hampshire, the attacks between the campaigns have become increasingly personal.

Clinton's statements and press releases in recent days have been carefully crafted to portray her as the candidate with the most foreign policy experience, who will be ready to take over in the Oval Office on day one.

She's also sharpened her attacks on Sanders' past positions on gun control, criticising him for voting previously against a bill that would have held gun manufacturers responsible to crimes committed by weapons sold legally.

It's been an attempt to portray the Vermont senator, who represents a sizable rural population of hunters and sportsmen, as being "pro-gun" even though Sanders has said repeatedly that he is in favour of enhanced restrictions - such as increased background checks - to ensure responsible gun use.

Although Clinton is facing tough competition in both Iowa and New Hampshire, she still has a sizable lead in national polls and scores highly with conservative and older Democrats, along with voters of colour.

Still, Sanders has captured the support of some of the same Democrats who came out strongly for President Obama in 2008 - young people looking for change.

While Clinton has sold herself as the candidate best poised to carry on the work started by Obama, Sanders has promised to implement further moves left - more socialist economic policies that appeal to young Americans who feel forgotten by the stagnant US economy.

Sanders has pledged, if elected to the White House, to work to overcome massive income inequality in the United States.

He's promising to expand healthcare and college opportunities for all Americans. He says he would break up the major banks and tax Wall Street corporations, many of which it's reported have donated heavily in the past to Clinton.

It's a message from Sanders that resonates with younger Americans who feel they have been left behind in the modern global economy.

With memories of 2008 on their minds, the Clinton campaign seems determined not to let history repeat itself with less than two weeks until the first presidential nominating contest in Iowa.

Clinton supporters are working to ensure that a once-inevitable lead does not slip away. That's why one can expect the Democrat discourse and debate on the 2016 campaign trail to get a lot less cordial.

 US Democrats spar in Iowa debate

Source: Al Jazeera