Jonathan Chait thinks he’s found President Donald Trump’s Achilles heel, and it’s not the Russia investigation or Stormy Daniels revelations. “The sheer breadth of direct self-enrichment Trump has unleashed in office defies the most cynical predictions,” Chait wrote in New York magazine’s latest cover story, noting that Trump “continues to hold on to his business empire and uses his power in office to direct profits its way.” But Trump is not alone, as “petty graft has sprung up across his administration,” Chait added. “Not since the Harding administration, and probably the Gilded Age, has the presidency conducted itself in so venal a fashion.”

Chait argues that this corruption is Trump’s greatest liability, and that the “best way” for Democrats’ to win in this year’s midterm elections “is to tell a very simple story. Trump represented himself as a rich man feared by the business elite. He had spent much of his life buying off politicians and exploiting the system, so he knew how the system worked and could exploit that knowledge on behalf of the people. In fact, his experiences with bribery opened his eyes to what further extortion might be possible. Trump was never looking to blow up the system. He was simply casing the joint.”

This case rests on an assumption that, in Chait’s words, “some kind of narrative focus is going to be necessary to frame the case against Trump.” But what if such focus isn’t necessary? What if Democrats shouldn’t campaign against Trump at all?

A Trump-centric approach might make sense in 2020, assuming he runs for reelection, but would be folly in this year’s midterms, when Trump is not on the ballot. The Democrats would be wiser to target the Republicans who control Congress, many of whom are on the ballot, and force them to defend an array of unpopular policies, notably on health care and taxes. To the extent that Trump factors into Democrats’ messaging at all, it could be in the GOP Congress’ complicity in his corruption, since they’ve abnegated their constitutional duty to check his abuses of power.

To campaign against Trump, rather than his party more broadly, runs the risk of making the election about a subject on which public opinion can’t be budged. Trump has had the flattest approval ratings of any president in almost a half century, according to a CNN analysis of Gallup’s weekly approval numbers. In FiveThirtyEight’s aggregation of public opinion polls, Trump in the last year has never sunk below 36.4 percent nor risen above 42.4 percent. This narrow range suggests that opinion on Trump is baked in: Those who support the president aren’t abandoning him despite his mounting scandals, and those who oppose him aren’t reconsidering their position in light of, say, the stock market’s gains since he took office.