Don't let anyone tell you that with a year to the US presidential election and more than three months before the first primaries, the Republican candidates' TV debates don't matter.

There have been three so far. The fourth will be on Tuesday night in Milwaukee. And not only have they attracted record audiences, they are moving polls.

 The Donald Trump spectacle

Donald Trump got a bump after the first one, Ben Carson after the second, and Marco Rubio after the third.

Carly Fiorina made it to the main debate for top tier candidates after her performance in the first 'undercard' debate.

So what are some of the things we need to watch for when the candidates take the stage in Wisconsin?

Firstly, can Jeb Bush live up to his new campaign slogan, "Jeb will fix it"? His poor performances up to this point have seen the one-time front-runner leak money and support to other candidates. He can't really afford to have another average night.

The big question for his campaign is, how to fix it? He had tried to be statesman-like and sit back from the fray and got hammered for low energy. He then went on the attack with other candidates and saw that returned with interest. He needs to make himself stand out.

Trump's ratings

It's also a big night for Trump. It's always a big night for Donald Trump, but he's seen his poll rating slip and he doesn't like it. A lot of people have asked if he's really campaigning to be president or just trying to engineer more publicity for himself.

He goes into this just days after guest hosting an iconic comedy show in the US and pulling in big ratings. But in this debate, he has to show he's serious, that his campaign is serious and not only does he want to be president, he has the ideas to actually be president.


RELATED: Jeb Bush wants to fix it


Carson is also in for an interesting night. He was in the lead in polls nationally before the last debate and has held that position for the past two weeks. But in that time, the US media has been crawling all over his previous public statements, his record and the claims he's made in presenting his story to the country.

He's complained he's being treated unfairly when he is actually being treated as what he is: the front-runner. He's told the media to move on - prompting at least two other candidates to tell him, he 'ain't seen nothing yet'.

Before he was the front-runner, he was able to make some comments like comparing President Obama's signature healthcare policy to slavery; saying he'd pull the US out of the United Nations and suggesting drone strikes on the US-Mexico border. He now faces increased scrutiny, and people will want to see if he handles that like a potential president.

Polished Rubio

Rubio saw his poll rating rise after the last debate in Colorado. He's been the most polished performer thus far, taking any question and turning to his personal narrative and making the point he wants to make. As I've said before, outside his core support he's becoming everyone's second favourite candidate. 

That's a good position to be in. But he is facing more and more questions about his financial affairs. He's answered them with little fuss and drama up till now. And he will be looking to lift his poll numbers even higher with another solid performance.

There's a change of format this time around. There will only be eight candidates on stage for the main debate. That means more time. The moderators will also be watched closely, given the row after the last debate.


Al Jazeera's Alan Fisher will be live-tweeting the debate: Follow him here


Many of the candidates claimed the questions were unfair and designed to provoke discord and personal attacks. Critics claimed the candidates didn't want uncomfortable questions which might expose their weaknesses.

Wisconsin has never hosted a candidates' debate before. It was picked as a host city 10 months ago, when the state's governor, Scott Walker, was riding high in the polls and was considered a good shot at the Republican nomination. He eventually dropped out because he couldn't convince enough people he'd make a good challenger for the presidency never mind take the top office himself.

His story is a reminder just what's at stake for those on stage.

Source: Al Jazeera