Some recent polls on the chances of U.S. presidential candidates have Republican candidate Donald Trump pulling ahead of Democratic candidate Hillary Clinton. With holdout supporters of Bernie Sanders, Hillary’s challenger within the Democrat Party, continuing to challenge her legitimacy as a candidate, and DNC chairman Debbie Wasserman Schultz being forced to resign over the Wikileaks email scandal, it may seem that Trump is benefiting from apparent divisions in the Democratic camp. But let’s take a step back. Is Trump winning in the polls? And if so, what does that mean at this stage? The answer to the first question is yes: Trump is leading all major polls. A CNN/ORC poll found the Republican nominee leading Clinton by five points, 44% to 39% in a four-way race (including candidates from the Libertarian and Green parties) and by three points, 48% to 45%, in a two-way competition. This news has generated surprise and in many cases concern in the U.S. and abroad about the prospect of a Trump presidency. Many are also surprised at how Trump’s numbers could have improved after a convention that saw his wife accused of plagiarism, his main rival give a speech refusing to endorse him and a concerted efforts by a minority of delegates to oppose his nomination to the very last. According to experts, however, nothing is out of the ordinary. It is normal for a candidate, even one as unorthodox as Trump, to see a bump in poll numbers after the party convention. Political scientist Dr. Christopher Wlezien of the University of Texas at Austin, co-author with Dr. Robert Erikson of Columbia University of The Timeline of Presidential Elections: How Campaigns Do (and Do Not) Matter, says that 56 years of data show not only that Trump’s gains are within the average (if not slightly below) but also, more importantly, that polling data taken in between the two conventions is not a the best available indicator of who is going to win in November. A more reliable statistical indicator of who is most likely to win would actually be the candidate leading two weeks after both party conventions. How likely? Well let’s just say it’s never been wrong: in the 16 presidential races since 1952 the candidate leading at that point has won the race 15 times, with the exception of 1980 when the polling was tied at that point in the race. “The first convention will cause a swing in one direction, the second causes it in the other direction. Once you get clear of that second convention you’re in a different spot then you were back before the first convention,” says Wlezien. Wlezien and Erikson’s studies show that the effects of conventions on polls have shown great variation: the poll bump of the first convention averages at 6.01 per cent (going as high as 15 per cent and as low as zero), while the second convention is almost the same at 5.9 per cent (ranging from .6 to 17 per cent). Other research has also shown that the candidate leading the polls in the winter-spring months is more likely to win than whoever is leading in the summer months. One explanation for the bump is simple. Conventions are effectively one-directional communication, and for several days viewers will only see one position expressed. “We’ve just come out of a week in which there was intense criticism of the Democrats at the Republican convention. Speech after speech criticizing Hillary Clinton personally and attacking the Democratic Party,” says political scientist Dr. Andrew Polsky, of Hunter College and the CUNY Graduate Center. “That message was very one-sided, it’s all that people heard for most of last week, the responses of the democrats didn’t get nearly as much attention,” says Polsky. “What we know about public opinion is that when all of the messages that people hear point in one direction, people go in that direction.” Statistics aside, many were surprised that Trump’s campaign could have benefited from a convention that appeared disorganised, divided and lacking the support (and presence) of many party leaders. But it’s important to remember that conventions often don’t go as planned. The 1980 convention saw Senator Ted Kennedy challenging presidential incumbent Jimmy Carter all the way to the convention floor, and 2012’s Republican performance will always be remembered for actor Clint Eastwood’s poorly received mock empty-chair interview of President Obama. Despite moments of considerable embarrassment, Trump still succeeded in hammering home his message for several consecutive nights, and the polls show that some were at least temporarily convinced. “It’s not trivial,” says Wlezien of Trump’s gain in the polls. “It’s smaller in size by comparison with previous conventions on average, bigger than some…but it’s particularly important because the race is close.” To some observers it might seem that evident divisions between die-hard Sanders delegates and Hillary supporters at the Democratic convention may be indirectly helping Trump. Polsky says that he doesn’t believe it’s going to be a serious problem for the Democrats down the road. Delegates are chosen because they are the hardest working, firmest supporters of a candidate; their intransigence is not exactly surprising. With current polls showing 85-90 per cent of Sanders supporters intending to vote for Clinton, there’s not really anywhere else for them to go from here. “Bernie Sanders has said ‘we have to support Hillary Clinton, we have to defeat Donald Trump,’ so there’s no spokesperson for the anti-Clinton people in the Democratic Party going forward,” says Polsky. Can Trump triumph after coming out on top at a disorganised GoP convention? Can Hillary overcome a rather exaggerated display of divisions at the DNC? One thing is certain: the candidate leading the polls two weeks from now is very likely to be the next President of the United States.