So, too, with the specific cases that the Atlantic essay focuses on: Trump’s insouciance about Russian interference in the last presidential election, and his continuing attacks on law enforcement professionals over the probe into his campaign’s possible involvement with that interference. Just consider the following caveat that Wittes and Rauch append to their brief:

We don’t mean to deny credit where it is due. … Last year, pressure from individual Republicans seemed to discourage Trump from firing Attorney General Jeff Sessions and probably prevented action against Special Counsel Robert Mueller. Moreover, Republicans as a group have constrained Trump on occasion. Congress imposed tough sanctions on Russia over the president’s objections. The Senate Intelligence Committee conducted a serious Russia investigation under the leadership of Richard Burr. But the broader response to Trump’s behavior has been tolerant and, often, enabling.

So according to authors who are trying to convince Trump-skeptical Republicans to vote against every single G.O.P. politician on principle, many Trump-era Republicans have 1) defended and protected a sweeping probe into their president’s campaign and possibly his family’s finances; 2) passed legislation punishing Russia for its interference; and 3) conducted a “serious Russia investigation” from within the United States Senate. All of which seems like … quite a bit? Perhaps even a sign that many prominent Republicans are not really just “enabling” Trump at all?

Now it’s quite true that other Republicans, especially in the House, have run interference for Trump’s attacks on Mueller’s probe, and encouraged rank-and-file conservatives and frequent “Hannity” viewers to believe the worst about the F.B.I. and other “deep state” organs. But partisan attacks on a special counsel’s probe are not the same thing as a sustained presidential assault on democratic institutions. Nor are angry presidential tweets that lack any sustained follow-through: If the president yells about his persecutors and little or nothing happens — the Mueller probe continues, Rod Rosenstein keeps his job, etc. — what’s undermined is presidential authority, not the rule of law.

And if many House Republicans are working to enable Trump’s authoritarian instincts while various Senate Republicans work to constrain them, surely that’s cause for precisely the kind of discriminating thinking that Wittes and Rauch want their Republican readers to rule out — for praising Richard Burr and criticizing Devin Nunes, let’s say, or for hoping Republicans keep the Senate while not minding if they lose the House, or otherwise judging conservative leaders case by case rather than insisting that they’re all rubber-stamping an incipient dictatorship.

All judgments about a year-old presidency are provisional. It is very easy to imagine a scenario in which the Wittes and Rauch argument would become persuasive. For instance, if Trump were to actually fire Rosenstein and Mueller and close down the Russia investigation and Senate Republicans did nothing. Or, to be a little more imaginative, if Trump started overruling his own foreign policy team and making various unwarranted, Manchurian-candidate-style concessions to the Russians, and the Senate simply went along.

Or if he invaded a country and toppled its government without Senate approval, or if he began prosecuting journalists on dubious grounds, or if tried to unilaterally rewrite immigration laws, or if he ordered the C.I.A. to torture prisoners at black sites …

… aah, sorry, I became carried away with memories of the last two administrations, neither of which corroded democratic norms through Twitter outbursts and personal sleaziness, to their credit, but both of which made big norm-eroding moves on other fronts that Trump has not yet come close to matching.