Trump and his party may yet pay a big price for their contempt for women. Photo: Kena Betancur/AFP/Getty Images

One of the most important principles in political analysis is to remember that “a vote’s a vote.” Yes, trends in this or that demographic are important to note, and can be crucial under certain circumstances, and in certain places. But excessive focus on one kind of voter while ignoring the big picture is often a mistake, one usually made by those obsessed with identifying the flavor-of-the-year swing voter (most famously “soccer moms” and “office park dads”) and then ignoring everyone else. “Winning” one particular group, moreover, is overrated: It’s the margin of winning and losing that usually matters most.

Having said all that, sometimes the breakdowns on this or that very large demographic group are so large and dramatic that paying attention to anything else may be a waste of time. And as Ron Brownstein explains in his latest number-crunching exercise, it’s not just the Year of the Democratic Woman in terms of candidates running for office: Women are the key to a Democratic win this year, and to its magnitude.

Trump is exposing the GOP this fall to the danger of unusually high mobilization and margins among African American women. Trump also risks consolidating a historic realignment toward the Democrats among college-educated white women, many of whom have viscerally recoiled from his behavior and language — such as his tweet Monday about Manigault-Newman.

[P]olling continues to send mixed signals on whether Democrats can expect substantial inroads among the third large group of female voters: white women without a college degree. Gains among those women could be the critical final piece to creating a secure path to a Democratic House majority — opening opportunities in districts beyond the urban and suburban areas where Republicans are most vulnerable.

Yes, other differentiations between voters, such as education and race, remain important, but gender differences are pervasive:

Over the past month in Gallup’s daily tracking poll, Trump drew much higher approval ratings from men than women. That was true among whites with a college degree, whites without a college degree, Hispanics, African Americans, and members of other racial groups, according to figures Gallup provided to The Atlantic. In this week’s national Quinnipiac University poll, college-educated and non–college-educated white men, as well as minority men, were considerably more likely than women in the same groups to say they like Trump’s policies.

This isn’t just a “gender gap.” Men do not seem to be moving that much from their positions in 2016. But college-educated women are, and if white working-class women do as well, the Democratic “wave” would become much larger.

Brownstein emphasizes the importance of non-college-educated white women because it was a pro-Trump demographic group in 2016 that seems finally to be souring on the president, but he documents the potentially seismic shift underway among their college-educated counterparts, too:

[C]ollege-educated white women … typically lean Democratic, but usually by modest margins. Hillary Clinton carried 51 percent of them against Trump in 2016, and Democratic House candidates have not carried more than 52 percent of them in any election since 1992, according to exit polls; they only split them evenly with Republicans in 2016.

But polling points to the possibility of unprecedented advantages for Democrats with those women this year. In Quinnipiac polling from March, about three-fourths of college-educated white women said Trump did not respect women as much as men, and in July, nearly three-fifths said he’s racist. In the NPR/PBS NewsHour/Marist poll, exactly three-fourths said his behavior as president “embarrassed” them. Likewise, in this week’s Quinnipiac survey, two-thirds said they didn’t like Trump as a person, and more than three-fifths said they didn’t like his policies or approve of his job performance.

Those attitudes suggest these women may tilt sharply toward Democrats in November; for months, many public polls have shown that about 60 percent — sometimes slightly more, sometimes slightly less — prefer Democrats for Congress. Such a movement could lastingly shift many white-collar suburban districts away from Republicans.

White working-class women, on the other hand, could be the key to Democratic gains in those famous Rust Belt areas that won Trump the presidency in 2016. As Brownstein notes, as a group they seem torn between revulsion toward Trump’s style and behavior, and relative satisfaction with his policies and results. If, as we have every indication to believe, Trump plans to double down on his abrasive tendencies in hopes of energizing his base, he might pay a price with white working-class women, who could stay home even if they can’t bring themselves to vote for the Donkey Party.

It could matter a lot whether they turn out and also whether they are open to voting Democratic a bit more than in 2016:

Working-class white women are so pivotal to shaping Democratic opportunities largely because blue-collar white men appear so immovably behind Trump and the GOP. To expand beyond purely urban/suburban districts, Democrats believe they must replicate the winning equation demonstrated by Conor Lamb in his March special-election victory for a House seat near Pittsburgh. His model was to max out his advantage in white-collar suburbs recoiling from Trump while narrowing his deficit in blue-collar and rural communities, almost entirely by improving among working-class white women.

Depending on the district, a strong turnout among minority women — whose hostility to Trump is reaching record proportions — could make a big difference too.

Exit polls showed Democrats carried 91 percent of black women in the Virginia governor’s race won by Ralph Northam, and an astounding 98 percent in the Alabama Senate race won by Doug Jones.

The focus on health-care issues among so many Democratic candidates regardless of gender is a tribute to their salience among women voters generally. And in 2016 pro-Trump districts, reminders of the president’s many broken economic promises are well-designed to bring non-college-educated white women over the line or leave them so discouraged that they abstain.

In any event, the nomination of so many women as Democratic congressional candidates this year is exquisitely timed. Unless Republicans can find a way to regain ground among college-educated women, keep white working-class women engaged, and rev up MAGA men, their odds of hanging onto the House or increasing their margins in the Senate are limited. To put it another way, the final accounting for the grossly porcine qualities Trump displayed so graphically in the Access Hollywood videos, and that the GOP accepted so cravenly when those videos didn’t kill his candidacy, hasn’t occurred just yet. Trump and his party richly deserve a Year of the Woman that makes all their sexist slurs about Hillary Clinton (and Nancy Pelosi and Maxine Waters and Elizabeth Warren) turn bitter in their mouths. And they may well be steadily losing women one vote at a time.