The longer an American has stayed in school, the more likely he or she is to register to vote and to cast a ballot on election day.

At one extreme, in the 2012 presidential election just 21.6% of adults who left school before ninth grade voted. At the other, according to statistics from the Census Bureau, 74.7% of adults who had an advanced degree voted. Though the precise numbers may not be known, observers are aware of the link between education and voting – it’s one of the clearest correlations in political behavior research.

It’s generally assumed that an education – for those who are able to afford it – improves civic engagement: that educated people feel they have a greater stake in society and feel it is worth their time to vote. In terms of shaping outcomes in 2016, though, it’s not just turnout that matters – the way educational status tends to align with party inclination counts too.

Again, the results are pretty clear. The Democratic party is preferred by college graduates, even though as recently as 2002 that was not the case. That’s partly because non-white Americans now make up a larger share of the college population, and those voters are less likely to be Republican.

This election has been dominated by headlines about the non-college educated white Americans who form Republican nominee Donald Trump’s support base. In 2012, about 55% of that demographic group showed up to vote, and 60% voted Republican.

Photograph: Pew Research Center

To understand how those people might affect this election, consider a few different hypothetical scenarios:

1. Non-college educated whites are no less likely to be Republican in 2016 and 100% of them show up to vote – which, let’s face it, would never happen. According to polling analysis site FiveThirtyEight’s calculations, Hillary Clinton would still narrowly win, by two percentage points.

2. Non-college educated white people are no more likely to vote, but 98% of those who do vote, vote for Trump – which, again, is never going to happen. Trump would win by a landslide of 27%.

3. Now consider a more realistic final hypothesis. Non-college educated white people become a little more Republican and a little more likely to vote – let’s suggest that turnout rises to 65% from 55% and Republican vote share rises to 70% from 60%. Trump would win the White House with 52% of the national vote.

All of these scenarios, however, assume that nothing else has changed since 2012 – that other educational groups like college graduates and other racial groups show up in the same numbers, with the same voting intentions, as they did four years ago. Clearly, that won’t be the case. This election has repeatedly shown that no party can afford to rest on its laurels about whom it can count on to vote.