Between Richard Nixon’s election by the silent majority in 1968 and Donald Trump’s stunning victory in 2016, there have been six conservative waves that swept Republicans into office. Disaffected white voters without college degrees have been the driving force in all of them.

This is surprising not only because these voters were once the backbone of the Democratic coalition, but because they have steadily declined as a share of the electorate. The percentage of white voters without college degrees fell from 83 percent in 1960 to 36 percent in 2012. It was 34 percent this year.

So why did they matter as much as they did in 2016? For one thing, Trump’s 39-point lead among less well educated whites surged past Mitt Romney’s 25-point margin. This was enough to make up for the fact that Trump’s margin of victory among whites with college degrees, at 4 points (49-45), was well behind Romney’s. (Romney carried college-educated whites by 14 points, 56-42.)

Despite their declining share of the electorate, these voters continue to exercise an outsize influence: as the Silent Majority of 1968 and 1972; the Reagan Democrats of 1980; the Angry White Men of 1994; the Tea Party insurgents of 2010; and now the triumphant Trump Republicans of 2016.