The Republican is using Britain’s shock exit from Europe as his mantra. Are his Democratic opponent’s numbers good enough to ward off another surprise?

Outside Trump Tower, the war looks to be over. As smoke clears from weeks of political bombardment, White House watchers are convinced the only questions now are how big Hillary Clinton’s win will be and whether the Democrats can take Congress, too.



Those Republicans still loyal to Trump cling to the hope that all the polls are wrong – that in barely two weeks’ time, angry voters will again stun the world. Over and over, Donald Trump is saying one word: Brexit.

“We will win,” he told a rally in Pennsylvania on Friday. “We will shock the world. This is going to be Brexit-plus.”

Earlier, in North Carolina, he promised to go “beyond Brexit”. By evening, “Brexit times five” was coming.

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On one level, the pep talk is not as crazy as it sounds. Not only has Trump confounded expectations all year, but like those campaigning for Britain to leave the European Union, he has closed within touching distance of his opponent several times already.

Four weeks ago, on the morning of the first presidential debate, his position in key swing states was so strong that the statistician Nate Silver estimated his chances of overall victory at more than 45%. After the Republican convention in July, Silver briefly projected Trump would win.



As in the case of Brexit, average poll numbers tilted back in favour of the status quo. The murder of MP Jo Cox was credited with shocking the British electorate back into a two-point poll lead for Remain by the time of the referendum. Outrage over a tape of Trump boasting about sexual assault precipitated his latest popularity slide and left Clinton with the near-six-point lead she now enjoys.

But Britons proved less ashamed of Brexit’s dark reputation once they were inside the privacy of a polling booth, eventually voting in favour of leaving by a nearly four-point margin. What if US pollsters are missing shy Republicans? Or failing to account for Trump’s ability to inspire people to turn out in greater numbers?

It is certainly a complacency Democrats wish to avoid. Fortunately for them, this may be where the similarities with Brexit begin and end.

Playing the system

The biggest difference can be seen as a combination of America’s voting system and its political tribes.

A simple majority of the national popular vote was enough to rewrite Britain’s relationship with Europe, but US presidents are required to win a majority of electoral college votes, which can be decisively achieved with a series of wins at the state level. In 1984, for example, Ronald Reagan secured 97.6% of the electoral college votes with 58.8% of the popular vote, because Walter Mondale lost every state except Minnesota.

Even if she defeats Trump in Republican strongholds like Texas, Utah, Arizona and Georgia, Clinton is unlikely to ever match Richard Nixon’s landslide over George McGovern in 1972 or Lyndon Johnson’s epic defeat of Barry Goldwater in 1964, for the simple reason that America has become more politically polarised in the years since.

Facebook Twitter Pinterest A woman is moved to tears as Trump takes the stage at a campaign rally in Newtown, Pennsylvania. Photograph: Jonathan Ernst/Reuters

But even a relatively small lead in the popular vote can translate into a decisive win, as Barack Obama found when he went into the 2012 election just 0.2% ahead of Mitt Romney in the polls yet emerged with a four-point majority in the popular vote and nearly two-thirds of the electoral college.

How will the election be decided? The president is chosen through the electoral college, in which each state is assigned a ​certain ​number of ​votes called ​electoral votes (EVs) ​. Electoral votes (EVs) ​, ​which are tied ​ultimately based on population. California has the most EVs, with 55; eight of the least populous states have only three apiece. Most states give all their electoral votes to whichever candidate wins the state popular vote. ​ as state after state reports results, the candidates' tallies build. Whichever T ​A presidential candidate who claims ​ a majority – ​ at least 270 ​out ​of the 538 EVs ​– ​wins the election. ​Many states' preferences are clear beforehand, thanks to p ​ Polling and precedent mean the preferences of many states are clear beforehand, resulting in a focus on "swing" states ​. The focus on election night is on "swing states" that could go either way ​. Donald Trump needs a sweep of swing states (watch Ohio, Florida and North Carolina, among others) to win.

It is less clear whether a big swing in the presidential race will make it more likely that voters pick senators and congressmen from the same party. Anxious Republicans are urging voters to “split their ticket”, to prevent Clinton accumulating too much power. Nonetheless, projections point to a growing likelihood that Trump’s woes will help Democrats take back the Senate and a small but rising possibility the same could happen in the House of Representatives.

Demographic changes also suggest a clear win for Democrats on 8 November. The white men who favour Trump may do so in part out of resentment that they no longer control the country so completely as they did, but the Democrats’ far larger lead among female, African American, Asian and Latino voters is likely to only grow as the country diversifies. As each side adopts the insults of the other as a badge of pride, Clinton’s “nasty women” and their allies simply outnumber Trump’s “deplorables”.

Charts reveal other lines dividing the US in 2016. Educational attainment, often a proxy for class in a country that doesn’t like to talk about it, is particularly indicative. College-educated voters flock to Clinton’s message of optimism about the economy while those without degrees are among the biggest supporters of Trump’s thesis that the system is rigged.

Trump’s comments about race and immigration have also polarised voters, driving non-whites back toward the Democratic coalition built by Obama but appearing to shock some white voters less.

And, if it is about anything, this election is about gender. Although men overall may now lean narrowly toward Clinton after a month of Trump’s misogynistic outbursts, it is striking that the average white American male is still pro-Republican.

The unpopularity contest

Of course, opinion pollsters can get demographics wrong too. Polls that listen to registered voters are better predictors of electoral outcomes than polls that listen to anyone who’s willing to talk. But those polls still aren’t perfect, partly because before voters actually vote, they’re just people and people change their minds. Especially a long time before election day.

That’s why now, with just over two weeks to go until the US votes, the polls are far more accurate than they were months ago. A lot has happened over those months – two party conventions, three debates and 10 allegations of sexual assault against one candidate. After all the boosts and dips, the overall effect has been that Trump has fallen in popularity while Clinton has risen.

Or, to be more specific, the polls show that Trump’s unpopularity has risen while Clinton’s has fallen. Both candidates are disliked by the majority of Americans.

But it is not just Brexit and Romney that have given polling methodology a bad name. There has been a string of polling failures: the Israeli election, the Scottish independence referendum and the last UK general election. If anything, the problems of polling have got worse since those votes, partly because it is getting even harder to contact people who are willing to share their voting intention.

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Still, though polls will not perfectly predict the US election, state by state and down to the decimal point, they are likely to accurately guess who will win nationally, especially if Clinton has a large enough lead.

The accuracy of polling in this election will hinge on the margin of error. Buried in the methodology of most polls is a note that says something along the lines of “margin of error: ± 4%”. It means if you repeated the poll 100 times with different respondents each time, the overall results would be within 4% of the results in at least 95 of those 100 polls.

Right now, Hillary Clinton’s polling average is 48% and Trump’s is 42%. If the margin of error on those numbers is ±4%, that means Clinton’s support could be as low as 44% or as high as 52% with Trump’s somewhere between 38% and 46%. The bigger the gap between the two candidates, the less the margin of error matters.

The margin of error in this election could well be more than 4%, because polling has become less accurate. For Clinton supporters to really sit back and relax, the candidate needs to widen her lead to the extent that even if the polls are wrong on the numbers, they are still right about the result.