If you thought that Donald Trump’s bowing and scraping to Vladimir Putin in Helsinki would put a big dent in his approval ratings, think again. Two new polls suggest that the President standing next to his Russian counterpart and publicly questioning U.S. intelligence findings about Russian interference in the 2016 election didn’t change anything much. That’s a testament to the unprecedented level of polarization in the American electorate. And it suggests that, as the midterms get closer, Trump will descend further into race-baiting and demagoguery as a way to keep his supporters engaged.

The weekly Gallup poll, which was released on Monday afternoon, estimated Trump’s approval rating at forty-two per cent, which represents a drop of one percentage point from the previous week. The latest Wall Street Journal/NBC News survey, which was released over the weekend, put Trump’s rating at forty-five per cent—a one-point gain since last month. Since there are substantial margins of error attached to both polls, the over-all picture that they draw is one of stasis. Most Americans disapprove of the rogue President, but Trump’s base of support remains solid, and it encompasses more than eight in ten self-identified Republicans.

It isn’t that all G.O.P. supporters were blind to what took place in Finland. According to a Washington Post/ABC News poll published on Sunday, almost a third of Republicans disapproved of Trump publicly expressing doubts about U.S. intelligence findings. By recent standards, that’s a significant defection from the pro-Trump line. But any concerns that Republican supporters had about the Helsinki summit don’t appear to have adversely affected their over-all level of satisfaction with Trump. In the Wall Street Journal/NBC News poll, eighty-eight per cent of Republican voters said that they approved of the job he’s doing. For this poll, that was the highest figure of his Presidency so far.

The resilience of Trump’s support among self-identified Republicans helps explain why elected G.O.P. officials are so loath to cross him, and it can be explained in various ways. Some analysts see it as a reaction to the negative media coverage that Trump receives, especially after controversial incidents like his press conference with Putin. “The more Trump gets criticized by the media, the more his base seems to rally behind him,” Fred Yang, a Democratic pollster from Hart Research Associates, one of the firms that carried out the new Wall Street Journal/NBC News poll, said.

Doubtless, this is part of the explanation. There may also be something of a statistical illusion at work. In many polls, the proportion of self-identified Republicans has declined significantly since Trump was elected, suggesting that some anti-Trump G.O.P. supporters may have left the Party, leaving him to garner a bigger share of support among a smaller base. In this case, as FiveThirtyEight’s Nate Silver argued on Monday, the headline poll figures may be misleading. But Charles Franklin, the founder of PollsandVotes.com, pointed out that the number of self-identified Democrats has also declined, and he suggested that the over-all impact of these shifts is likely to be pretty small. In a close election, however, they could still prove significant.

Regardless of the underlying reasons for them, the new poll figures will surely only encourage Trump to believe that his incendiary tactics of attacking the media and fanning resentments about immigration, race, and unfair foreign competition are working. As we get closer to Election Day, he seems certain to escalate this strategy.

Perhaps foreshadowing what is to come, Steve Bannon, Trump’s former campaign manager and political strategist, told CNN’s Fareed Zakaria last month that the midterms would be a “base-plus” contest. Bannon argued that Trump should seek to “nationalize the election” around his signature theme of immigration. Although the White House subsequently modified its inhumane policy of separating migrant families at the southern border, the President, in his public appearances and on his Twitter feed, continues to emphasize “strong borders,” his proposed wall, and the threat represented by the MS-13 gang.

The scaremongering seems to be working. In a Gallup survey published last week, thirty-five per cent of Republicans named immigration as the top problem facing the country, the highest proportion in more than a decade. “The 35% of Republicans who say immigration is the country’s top problem is over twice as high as the 15% who mention government,” Frank Newport, Gallup’s editor-in-chief, noted.

In addition to whipping up fears about nonwhite immigrants, Trump appears eager to rekindle his dispute with black football players. Last Friday, after the N.F.L. and the players’ union announced that they were taking a timeout from resolving the dispute about some players kneeling in protest during the national anthem, Trump tweeted, “The NFL National Anthem Debate is alive and well again - can’t believe it! Isn’t it in contract that players must stand at attention, hand on heart? The $40,000,000 Commissioner must now make a stand. First time kneeling, out for game. Second time kneeling, out for season/no pay!”

Of course, none of this means that Trump’s divisive tactics will necessarily succeed in helping his party in November. For all his support among self-identified Republicans, he is still one of the most unpopular Presidents in history—if not the most unpopular. And his party isn’t doing much better. Recent polls show the Democrats retaining a seven- or eight-point lead in the generic congressional vote, which many experts believe is roughly the margin of victory that the Party needs to take control of the House of Representatives.

Trump’s apparent determination to insert himself into the race and stir things up will only provide more fuel to the Democratic “resistance,” whose entire strategy is based on turning the election into a referendum on his Presidency. In Republican-majority states, a Trump on the rampage may help some Republican candidates. But in left-leaning states, such as California and New Jersey, G.O.P. incumbents will be trying to localize their races and deëmphasize Trump. But that may well prove an impossibility: although Trump’s name won’t be on the ballots, he is set to be an all-consuming presence.