Thousands of people participated on Jan. 21, 2016, in the Women’s March on Washington. (Sarah L. Voisin/The Washington Post)

There was a theory before the 2016 presidential election that Donald Trump’s political rhetoric and personal history might turn the election into a rout. Women, it was theorized, might balk at voting for the Republican at unprecedented levels, making it all-but-impossible for Trump to win the White House.

Obviously, that didn’t happen. While Trump did receive fewer votes, he won the electoral college and the presidency. Women backed Hillary Clinton, according to exit polling, but by a margin generally in line with how they’d voted for Barack Obama in 2008 and 2012. Men backed Trump by about the same margin as they had George W. Bush in 2000 and 2004.

Despite Clinton’s loss, 2017 has been a year in which there’s been a noticeable shift in the demonstrated power — political and otherwise — of women: more women running for office. A massive protest/rally in Washington in January. Uncovering decades of sexual harassment and abuse at the hands of powerful men. Clinton once said that the “future is female”; the present seems to be, too.

At Axios, Mike Allen speculates that this might have an effect on the 2018 elections.

“Trump won narrowly, and his unprecedented coalition included many suburban and exurban women who couldn’t stomach Hillary Clinton,” Allen wrote. “If those voters were to tip dramatically to Democrats in 2020, Republicans would suddenly have a massive math problem.”

Unless men tipped the other way.

Consider what happened in 2016. Last November, women preferred Clinton by about 12 percentage points and men preferred Trump by about the same margin, according to exit polling. For women, that was a 1-point shift to the Democrats relative to 2012. For men, it was a 5-point shift to the Republicans. At the same time, the percentage of the electorate that was female declined and the percent that was male increased. That combination meant victory for Trump, however narrowly.

There are margins of error here that add gray area around all of the calculations, but the pattern in recent presidential elections is fairly consistent. The chart below shows exit poll results since 1976 (as compiled by Cornell’s Roper Center). Since 1992, women have consistently backed the Democrats and consistently made up more than half of the electorate. The vote among men has varied more often during that period.

The more immediate question for 2018 is how women and men have voted in House elections. Last year, the margin between men and women in the presidential election was the widest it has been in any presidential election since 1976. Interestingly, the margin of support for Democratic House candidates by women matched the highest since 1994.

As with the presidential results, there’s been a consistent pattern in House voting since 1992. More women voting, and they are more likely to vote for Democratic candidates.

Since 1992, though, there have only been three elections in which the Democrats won a majority of the House: 1992, 2006 and 2008. (Democrats won more votes in 2012 but not control of the chamber.)

Those are also the only three races since then in which men have backed Democrats more heavily in House races.

The one election where women backed Republicans more heavily than Democrats was in the Republicans’ 2010 rout.

On the column chart above, you’ll notice that the three elections with the smallest difference between how men and women voted were also 1992, 2006 and 2008, when women were more likely to support Democratic candidates by 6, 8 and 8 points respectively. This is largely because men moved to the left. In no election since 1992 have men backed Republicans more heavily in exit polling and Democrats won more House seats.

That’s the question raised by 2017. Will there be a rejection of Republican candidates by women and, if there is, to what extent would it offset the vote of men?

The most recent Post-ABC poll asked Americans how they plan to vote in the 2018 House races. The Democrats hold an 11-point advantage on that question.

Among women, Democrats are preferred by 20 points. Among men, it’s tied.