USA: Who is running for president in 2016? Find out from the article!
The clash between Donald Trump and Hillary Clinton is set to be brutal, with America being dominated by the race to replace Barack Obama in the White House.
Until election day on 8 November, follow our poll tracker to keep on track on with who's top. It takes an average of the last five polls published on RealClearPolitics.
19 May 2016 was the first time that Republican Donald Trump pulled ahead of Democrat Hillary Clinton in the average of national polls. He was 0.2 percentage points ahead of Clinton on May 22, leading to someclaiming "it's probably time to panic" - although the next poll put Clinton back ahead.
Clinton had held a lengthy double-digit lead over Trump, who was once a Republican outsider. This has been eroded by the popularity of Trump, although it has somewhat opened up again after she secured apledge to work together from her Democrat rival, Senator Bernie Sanders.
Trump's polling had previously drawn close to Clinton's during last October, as his appearance on Saturday Night Live coincided with Clinton facing pressure in a trial on the deaths of four Americans in Libya in 2012.
Following a series of gaffes by Trump, the Republican nominee has seen Clinton get ahead in the polls again, now maintaining around a six point lead.
A word of caution, however: polling so far away from the election is unlikely to be reflective of the final score. A lot can change.
At this stage of the race in 2004, as Nate Silver notes, John Kerry had a similar lead over George W Bush as Clinton's current lead over Trump.
The New York Times has also worked out that, at the the convention stage, a simple polling average has differed from the final result by about nine percentage points. So, with the polls being so close, anything could still happen.
Why are the US election polls so close?
One of the reasons that the polls had been closing is that the Republicans were rallying behind Trump. This has since been put under jeopardy, as a couple of big party figures refused to endorse the nominee.
Meanwhile, a recent YouGov poll showed that just over half of supporters of Bernie Sanders - Clinton's Democratic rival - would back Clinton.
Sanders also polled better against Trump than Clinton, while he was still in the race. 61 per cent of his backers viewed Mrs Clinton unfavourably, while 72 per cent say she is "not honest and trustworthy".
Despite this, Sanders has pledged his support for the victorious Democrat nominee, saying: "This campaign is not about Hillary Clinton, Donald Trump, Bernie Sanders or any other candidate who is standing for president. This campaign is about the needs of the American people."
Still, Clinton holds a big demographic advantage over Trump. AWashington Post poll indicated that 69 per cent of non-whites and 52 per cent women favour Clinton, while 57 per cent of whites and men support Trump.
What about the American states?
When it comes to the final presidential race, the Democrat and Republican candidates will go head to head to win the 50 American states. Each state has a certain number of electoral college votes based on population.
This system matters, as the popular vote is less important than the electoral college vote. If Clinton's campaign is buoyed by big Democratic states such as New York, New Jersey, Illinois and California, these populous states could lead her to victory.
For example, in 2008, Barack Obama won 53 per cent of the vote - but this led to 68 per cent of the electoral college vote. Such highly populated states played a large role when they backed the current president.
Swing states - states that regularly switch between Democrat and Republican between elections - are also important.
States like Arizona, Florida, North Carolina, Ohio and West Virginia have the power to swing the election. So far, neither Trump nor Clinton has a significant lead in these crucial states.
US Election 2016
What are the odds on the American presidential election?
It has long been said of predicting sporting outcomes that the bookies don’t get it far wrong, working out probabilities with complicated mathematics based on the choices of their thousands of paying punters.
After last year’s surprise General Election result, many political followers have lost faith in pollsters and prefer to look at the odds to predict the future.
Hillary Clinton has been odds-on favourite since the end of February, but Trump has steadily caught her up as his Republican rivals dropped out. Last July he was a 25/1 shot while Hillary was already at evens.
Ladbroke's latest odds for the next US president are:
Hilary Clinton 1/4
Donald Trump 3/1