As Donald Trump left the White House on Monday for his final three campaign rallies of this electoral season, he said, “There is a great electricity in the air . . . like we haven’t seen since, in my opinion, the ’16 election.” But Trump also downplayed expectations for what will happen on Tuesday, noting that, for a century, the party of incumbent Presidents has done badly in midterm elections.

This cautionary tone was also evident in statements by other White House officials, and it reflected the latest opinion polls, which still point to the Democrats taking control of the House of Representatives and the Republicans clinging to a narrow majority in the Senate. Indeed, if anything, the latest surveys suggest that the opposition party has made up a bit more ground in recent days, as Trump has flown around the country vilifying immigrants and portraying Democrats as dyed-in-the-wool socialists.

In the battle for the House, one way to gauge recent trends is to examine the results of the extensive polling carried out over the past couple of months by the New York Times’ Upshot team and Siena College. A great merit of this mammoth exercise is its transparency: the data is public and can be analyzed. “With the final Upshot data files in, we can now say that Democrats did in fact close strong in the battlegrounds. Individual-level poll response modeling shows them +3% from the early September baseline,” Patrick Ruffini, a Republican polling expert, wrote on Twitter on Monday.

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In the Senate, too, where the Democrats need to pick up two seats to overturn the G.O.P. majority, there are suggestions that at least some of them are finishing with momentum. In Missouri, according to the Real Clear Politics polling average, Claire McCaskill, the embattled Democratic incumbent, is back in a virtual dead heat with the Republican Josh Hawley. In Nevada, the Democratic challenger, Jacky Rosen, has tied things up with the Republican incumbent, Dean Heller. In Florida, the Democratic incumbent, Bill Nelson, has slightly increased his lead over the Republican challenger, Rick Scott. Over all, however, the polls still point to the G.O.P. maintaining control. Indeed, FiveThirtyEight’s polls-based forecasting model says that there is an eighty per cent probability of this happening.

Of course, the 2016-inspired health warning about the reliability of opinion polls needs to be taken seriously, especially as many races look scarily close, including the aforementioned Senate contests and the thirty House match-ups that the Cook Political Report still rates as “toss-ups.” Moreover, the early-voting tallies in places such as New Jersey and Virginia suggest that there will be a very high turnout, which could affect the outcome. “With so many close contests, even modest late shifts among undecided voters or a slightly unexpected turnout could yield significantly different results,” Nate Cohn, of the Times’ Upshot team, noted on Monday.

To take control of the House, the Democrats need to flip twenty-three G.O.P.-held seats. As I wrote on Friday, there is a plausible scenario in which a “blue wave” materializes and the Democrats pick up more than forty seats, getting a healthy majority. But there is also a scenario in which the Republicans do better than expected in both chambers, partly because they can fall back on some built-in advantages based on geography and gerrymandering. Still, after taking into account all the possibilities, the White House and the G.O.P. leadership have plenty to worry about, particularly in the suburbs, where American elections tend to be won and lost.

Ever since Trump was elected, it has been evident that his style alienates many college-educated suburban voters, particularly women. This pattern is very much present in the latest data. Consider New Jersey’s Seventh District, which sprawls west from Essex County, near New York, and is home to Trump’s Bedminster golf club. Tom Malinowski, a former Obama Administration official, has established a narrow lead in the polls over Leonard Lance, a Republican congressman who has held the seat since 2009. About four out of five voters in the district are white, and a majority have a college degree. Among white college-educated voters, according to a poll by Monmouth University, Malinowski leads Lance by fifty-seven per cent to thirty-seven per cent. There is also a big gender gap. Among women of all education levels, Malinowksi leads by seven points, whereas Lance is ahead among men by two points.

National polls show similar patterns. In the final preëlection poll of likely voters by CNN, sixty per cent of white college graduates said they would vote Democratic, and just thirty-eight per cent said they would vote Republican. That’s a gap of twenty-two percentage points. The gender gap was even bigger. Among likely voters, sixty-two per cent of women said they favored Democratic candidates, and just thirty-five per cent said they favored Republicans. (Among men, the Republicans had a one-point lead.) Other national polls have produced similar findings.

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Trump is betting he can offset these trends, not by pointing to the strong economy but by whipping up his Republican base with stories of “Middle Easterners” and violent gang members slipping into the United States as part of the migrant caravan, and of Stacey Abrams, the progressive Georgia Democrat who is making a historic bid to become the first black female governor of any U.S. state, turning the United States into Venezuela.

In the words of the Washington Post’s Philip Rucker, Trump has “taken his no-boundaries political ethos to a new level—demagoguing the Democrats in a whirl of distortion and using the power of the federal government to amplify his fantastical arguments.” According to a report by Politico, Paul Ryan, the Republican Speaker of the House, called Trump on Sunday and asked him to end the campaign on a more positive note, but it was already too late. On Friday, in West Virginia, Trump described predatory immigrants as “the worst scum in the world.” In Ohio on Monday afternoon, he said that the Democrats would “take a wrecking ball to our economy and to the future of our country,” and described their agenda as “a socialist nightmare.”

Two years ago, Trump’s inflammatory tactics took him to a narrow and unlikely victory, which explains why he has reprised them this year. But by purposefully nationalizing the campaign, focussing it on himself and his inflammatory agenda, Trump has also insured that, even more than usual, these midterms will be a referendum on the President. There are signs that the American electorate, or large chunks of it, will serve him a much needed rebuke. But, after 2016, nobody will rest easily until the last vote is in and counted.