The final hours: What do the polls say, and does the margin matter?

With only hours left before we learn the outcome of the US elections, ever greater attention is being focused on the polls, with policy – hardly a central feature in the debate, despite huge differences between the two candidates – receding farther and farther into the background. Meanwhile, three competing narratives, representing three possibilities about where the race stands, have taken hold in the public debate:

1. The election is getting noticeably closer and what looked like a very likely win for Hillary Clinton is now a much dicier scenario. This is statistician and journalist Nate Silver’s view, and given the extent to which he and his colleagues at the blog FiveThirtyEight are synonymous with electoral forecasting, it has received wide coverage.

2. The polls are basically accurate but represent factors other than actual voter intentions; an argument made by analysts at YouGov and the Princeton Election Consortium. Rather, in this view, the poll movements are oscillations around a fairly stable race in which Clinton has a three to four point lead over Donald Trump – which, if reproduced on November 8, would likely result in a comfortable Clinton win along similar lines as Barack Obama’s 2012 victory over Mitt Romney.

3. The third possibility – reinforced by the perception of most recent failed polling in the UK’s EU referendum and the Colombian plebiscite on the peace accord – is that the polls are simply wrong. That is to say, for a variety of reasons (Clinton’s gender, Trump’s unpredictability, the historically high unfavorable ratings of both candidates) pollsters are missing or misunderstanding the composition of the electorate which will ultimately decide the vote, making the result entirely unpredictable.

Regardless of their accuracy, polls do have some indirect effects. They drive media narratives, influence donors (both large and small) and can even convince campaigns to change their strategies: where the candidates and top surrogates spend the final few days before the vote, where they air their TV ads and so forth. They also set expectations for the post-electoral period. That’s especially pertinent this year, given the claims that Trump and his supporters have made about the election being “rigged”. While there is no actual evidence of meaningful voter fraud, Trump’s campaign has built an expectation that any close loss will be evidence of such.

So beyond the fundamental question of whether it will be Clinton or Trump standing on the Capitol steps on January 20, 2017, does the margin by which he or she will win really matter? Since the end of the primaries, Clinton has consistently led polling aggregates by greater or lesser margins. From that, and from the structure of the American electoral system, we can extrapolate that there is a greater range of possible winning margins for her than for Trump. In other words, Clinton may win by a small popular vote margin or a large one. Trump, by contrast, is more likely to win by a small margin or even (thanks to the mechanics of the Electoral College) a negative one.

While the margin might traditionally make a difference in terms of the extent to which it drives outcomes in Congressional and Senate races, there seems to be relatively little correlation this year in polling for Senate candidates and for the presidency. It seems as though individual candidates in those races will largely stand on their own merits – unless there is a very late-breaking wave of support for one side or the other.

Nor is the margin likely to matter much in terms of governing. The Republican Party has already started to delegitimize Clinton’s potential presidency, threatening to not confirm any Supreme Court justice she nominates and even to start impeachment hearings. The difference between a two-point and seven-point Clinton win will not change this dynamic. And nothing in Trump’s past behavior or rhetoric suggests that he would govern any differently whether he wins a solid majority or a bare majority of Electoral College votes.

Where the margin will matter is in the future of the parties themselves. A solid Clinton victory might give ammunition to those in the Republican Party who would argue that its nationalistic, anti-trade and anti-immigration positions are not sustainable on the national level, whereas a close victory is more likely to confirm that the future of the GOP is Trumpism (though potentially without Trump). On the other hand, a Trump victory will instantly reinvigorate the left-vs-center schism in the Democratic Party which has been largely subsumed over the last few months in the name of winning the election. A close call might have similar, if slightly more muted, effects, with the left arguing that Bernie Sanders might have won with a greater margin and possibly even ushered more Democrats into office in other elections. Those impacts, in turn, will define how the parties relate to each other.

So on November 8, while the fundamental question of who wins is undoubtedly the most important, the margin of the win is also likely to define what the next four years of American government will look like.