Should this happen, Congress and some judges will try to intervene. But Trump is growing ever more lawless and autocratic. “There is a near-systematic purge happening at the nation’s second-largest national security agency,” a senior administration official told CNN on Monday, speaking of D.H.S. The president is filling positions with acting officials, circumventing Senate confirmation. Some senior members of the administration, like Wilbur Ross, the commerce secretary, are flatly refusing to cooperate with congressional oversight. CNN reported that Trump told border agents to ignore judges when taking steps to keep migrants out. We should not assume that government institutions will restrain the president before he visits anguish and terror on thousands more of the world’s most vulnerable children.

What happens to Nielsen now can serve as an example to other people in the administration as they decide whether to just follow orders. By this, I don’t mean that people should scream at Nielsen in restaurants. Rather, those horrified by family separation should do whatever they can to deny Nielsen the sort of cushy corporate landing or prestigious academic appointment once customary for ex-administration officials. The fact that she evidently didn’t go as far as an erratic and out-of-control Trump wanted is immaterial; she should be a pariah for going as far as she did.

Coincidentally, the day before Nielsen resigned, a coalition of progressive groups signed on to a petition asking corporate America to blacklist senior people in the Trump administration, including Nielsen, who took part in crafting, enacting or defending family separation. “Allowing her to seek refuge in a corporate corner office or a boardroom, university, speaking agency or elsewhere poses a significant reputational risk for those involved,” said Karl Frisch, a spokesman for Restore Public Trust, the group organizing the campaign.

How much of a risk will depend on decent Trump-hating Americans. The Resistance has been flagging recently, even if abhorrence of Trump’s degenerate administration has not. Many people, having worked frantically to deliver the House to Democrats in the midterms, are exhausted. The crackup of the Women’s March, and the resulting tensions between some black and Jewish activists, has been deeply dispiriting. The beginning of the Democratic presidential primary has reanimated old intra-left animosities. And relentless outrage is hard to sustain, no matter how justified.

But with the possible return of family separation, the Resistance needs to regroup, and demanding a boycott of Trump officials tainted by baby-snatching is a good place to begin. Such a boycott would take advantage of one of the central asymmetries in American life. Rural voters, who tend to be conservative, have disproportionate political power; it’s why Trump, who lost the popular vote, is president in the first place. But cosmopolitan progressives have disproportionate economic and cultural power, which is why we have the faintly absurd phenomenon of woke capitalism. That power should be deployed to force the sort of accountability Nielsen reportedly fears, and to serve as a warning to others that the Trump stink never washes off.