He knows that the Democratic leadership wants to distance itself from the squad. He also knows that he is hated intensely by the rank and file of the Democratic Party, and that its leadership feels commensurate pressure to vocally defend any Democrat he attacks (especially when he tells lies, like saying that Omar is pro-al-Qaeda).

Trump hopes to characterize those defenses as expressions of support not only for the individual members of the squad, but also for their agenda. That, he thinks, will persuade voters wary of leftist politics (or strongly attached to Israel) to stick with him.

Given Trump’s low approval rating, the many scandals associated with his presidency, and his failures to build a border wall, transform America’s infrastructure, improve health care, or end America’s foreign wars, running against the squad and socialism may well be a more promising strategy than running on his own record.

But the obvious effect of his actions is to elevate and strengthen the squad. Although most Americans don’t agree with the squad’s agenda and don’t want the left wing of the Democratic Party to drive the national debate, Trump is boosting the members’ name recognition, the media attention they get, their social-media followers, their war chests, and sympathy for them in the Democratic caucus, which will reliably rally around anyone Trump disparages.

That’s not to say the attacks aren’t personally hard for members of the squad to endure. As Daniel Larison wrote at The American Conservative, “Falsely claiming that someone is ‘pro-Al Qaeda’ is one of the most despicable things someone could say about any American, and to say it about a Muslim American is particularly dangerous and obnoxious ... Rep. Omar has already received numerous death threats, and the president’s attacks on her are guaranteed to lead to even more.” Trump’s lies may well be putting Omar’s life in danger.

But the fact is, he is simultaneously helping to boost the squad’s influence in American life.

Imagine if Hillary Clinton started going on Twitter and CNN every day attacking Representative Devin Nunes. Do you think that would help or hurt his ability to raise funds, go on TV, influence public debate, win reelection, and increase his name recognition, paving the way for future opportunities?

In this dysfunctional, nihilistic climate of negative partisanship, where many Americans act based on what they hate more than on what they love, a politics dominated by Trump and the squad attacking each other can plausibly increase the standing of both at the expense of politicians that better represent majority views.

Squad members can justify their focus on Trump by pointing out that they can hardly avoid criticizing the president, Republican standard-bearer, and most powerful man in the world. Trump has no similar justifications. If he believes even half of the negative things he says about the squad, then one can only conclude that he is trying to help his chances of getting reelected at America’s expense.