The American people were shaken this week by the images of President Trump’s cruel treatment of immigrant children. His posturing, lying and indifference to the consequences of his actions have not worked well for him.

Interestingly, they seem also to be increasingly wary of his “L’état, c’est moi” impulses. A new Associated Press-NORC Center for Public Affairs Research poll finds that “85 percent think it would be unacceptable for presidents to pardon themselves if charged with a crime, and 76 percent think Congress should take steps to remove a president from office if they did so.” There is a partisan gap, but a strong majority of Republicans disapprove of a self-pardon (75 percent) and would favor impeachment if he tried (56 percent). It seems we have found a Trump proposition that even Trump worshipers can agree is bunk. (“The survey did not ask about Trump by name, but several poll respondents in follow-up interviews — including some strong Trump supporters — said their feelings would not change when applied to the current president.”)

Aside from the political uproar it would cause, it is hard to imagine that Trump would rely on a “self-pardon” given that he could have no confidence it would work. If he self-pardoned and then was indicted, courts could very well agree with what the Office of Legal Counsel opined days before Richard Nixon left office: “Under the fundamental rule that no one may be a judge in his own case, the president cannot pardon himself.”

What does that mean? In practical terms, if special counsel Robert S. Mueller III finds evidence sufficient for a crime (though when the president can be indicted is a matter of legal debate), Trump, unless he wants to risk jail, would need to obtain a pardon from the only person who can be sure to give him one: Vice President Pence, who would need to ascend to the presidency to give Trump his get-out-of-jail-free card. When Mueller, as we expect, comes forward with manifold evidence of obstruction of justice, Trump will need to think about leaving office before Pence does. That might not happen immediately, but for some period of time (a day, a week, a year), Trump has to guarantee that a legitimate and reliable pardoner is president. (Incidentally, if Pence follows through and pardons Trump, his political career for all intents and purposes is over; even Gerald Ford — who enjoyed the benefit of the doubt in a much less-polarized environment — lost in 1976.)

This raises a host of interesting questions. Could Trump announce his intent to pull such a stunt? Would Congress then impeach him and Pence? Nevertheless, Trump’s assertion of the power to self-pardon is meaningless. If he tries it, he’s a goner politically and probably legally.

The pardon issue should inform Democrats when asked whether they favor impeachment. Democrats might be wise to say, “No, we favor criminal prosecution if and only if there is evidence of a crime, although prosecution may have to wait until he leaves office. But if he tries to self-pardon, all bets are off.” That’s a smart political answer, and it nicely highlights Trump’s dilemma.

Admittedly, we are getting ahead of the facts, but when one considers the mound of evidence that Trump sought to stymie the Russia investigation (firing former FBI director James B. Comey, coming up with a phony excuse for the firing, creating a false explanation for the June 2016 meeting at Trump Tower, dangling the prospect of pardons in front of key witnesses, repeatedly lying to the American people, threatening the special counsel, badgering Attorney General Jeff Sessions not to recuse himself so he could quash the investigation, creating false conspiracy theories to delegitimize the investigation, etc.), it becomes clear that Trump has a real risk of facing prosecution — and no simple way to prevent it.