A sign marks the entrance to an early voting station last month in downtown Minneapolis. (Steve Karnowski/AP)
Opinion writer

Democrats seem poised to take back the House majority two weeks from today, according to multiple polls and analyses. Voters are expressing plenty of enthusiasm to pollsters, registration numbers are reflecting an avalanche of new voters and campaigns are furiously trying to get occasional voters to the polls. But the truth is that we know much less than the news coverage suggests. We simply don’t know who will show up.

The poll numbers certainly should encourage Democrats. The RealClearPolitics average shows that Democrats hold a 7.7-point lead in generic polling. When Republicans took back the House in 2010, their lead was 6.8 points.

When you drill down on competitive races, Democrats again seem to be holding or extending their lead. The Post-Schar School poll of competitive battleground seats shows Democrats continue to lead narrowly in a great many races. The Post’s report shows “50 percent currently supporting the Democratic candidate in their district and 47 percent backing the Republican.” However, the close contests are being waged predominantly on Republicans’ turf. “The overwhelming majority of the districts surveyed — 63 of the 69 — are currently represented by a Republican in the House. Collectively these battleground districts voted strongly for Republicans in the 2016 election,” The Post reports. “The fact that the margins today are where they are illustrates the degree to which the GOP majority is at risk but also the fact that many individual races are likely to be close. Democrats need to gain a net of 23 seats to take control of the chamber.”

You will have a tough time finding evidence that the recent Supreme Court confirmation fight moved the needle for Republicans. The Post reports that “a majority of battleground district voters (57 percent) say they are concerned that men they are close to might be unfairly accused of sexual assault. But a far larger majority (78 percent) say they are concerned that women in this country are not believed when they report that they were sexually assaulted. Overall, by 59 percent to 41 percent, Americans say the bigger problem is that women who report that they were sexually assaulted are not believed.”

Women continue to be the backbone of Democratic support. (“To the degree that Democrats have any edge in these districts, it is because of support from women, as was the case in the previous poll. Among likely voters, men favor Republican candidates by 51 to 46 percent, while women back Democrats by 55 to 42 percent.”) College-educated women are flocking to Democrats, who hold a 23-point advantage in that department. Nonwhite voters favor Democrats 2 to 1, but interestingly, the GOP lead with whites is only 5 points.

The Cook Political Report suggests some momentum for Democrats:

An astounding 112 Democrats outraised GOP opponents in Republican-held seats between July and September. Of the 93 GOP incumbents who were outraised, 20 are currently in our Likely Republican column and 23 in Solid Republican. Democrats’ late dominance in the air wars could produce several Election Night surprises.

Today, we’re changing ratings in ten districts, including eight where Democrats’ position has improved. Democrats now have a clear advantage in 17 GOP-held seats and Republicans have an advantage in two Democratic-held seats. If the 30 Toss Ups were to break evenly between the parties (15 seats apiece), Democrats would score a net gain of 29 seats, six more than the 23 they need to retake the majority.

“Toss-up” seats don’t necessarily break exactly 50-50, and there will be some surprises (as there are in every election). Accordingly, Cook’s prediction finds “a 20 to 40 seat Democratic gain is possible, but right now the likeliest outcome is a Democratic gain of between 25 and 35 seats.” But let’s remember that polling of “likely” voters isn’t picking up those irregular voters who insist that they really will turn out this time.

In sum, tight races might break disproportionately in one direction or another. While that means Republicans might hold the House majority by the narrowest of margins, it also means Democrats’ gains could be much higher than currently predicted. The difference is in the number of pickup chances. Republicans have to defend dozens of seats to stay even, while wins in just some of the closest races will hand Democrats the majority. More than in any recent election, unpredictable turnout remains the greatest source of uncertainty.