Imagine, for example, that judges told a President Trump that he could not turn the Southwest border region into “a police state,” which the executive director of the American Civil Liberties Union forecast in a recent Post op-ed would be the result of Trump’s plan to deport 11 million undocumented immigrants. Imagine that Trump and his administration continued building camps anyway. Given the contempt that Trump has expressed for the judiciary, and the ignorance he has displayed of the Constitution, that scenario is not so far-fetched.

At such a moment, laws could not save you; only people could. Would members of Congress, career civil servants and others stand up to Trump and for the rule of law — and could they oppose him while remaining true to principle and not descending to his level?

On the first question, the evidence from Trump’s party is not encouraging. Republicans who months ago were clear about the danger that he represents have abjectly fallen into line, albeit with varying levels of enthusiasm. If House Speaker Paul D. Ryan (R-Wis.) cannot disavow a candidate he has accused of racism, why would we think he would be firmer when that espouser of racism lived in the White House?

The second question — could Trump’s opponents stay true to their own values? — is where the Ginsburg episode is discouraging.