Ross Douthat wrote last weekend:

Such an action would come equipped with legal justifications, of course. …

But the precedents would not actually justify the policy, because the scope would be radically different. Beyond a certain point, as the president himself has conceded in the past, selective enforcement of our laws amounts to a de facto repeal of their provisions. And in this case the de facto repeal would aim to effectively settle — not shift, but settle — a major domestic policy controversy on the terms favored by the White House.

This simply does not happen in our politics. Presidents are granted broad powers over foreign policy, and they tend to push the envelope substantially in wartime. But domestic power grabs are usually modest in scope, and executive orders usually work around the margins of hotly contested issues.

In defense of going much, much further, the White House would doubtless cite the need to address the current migrant surge, the House Republicans’ resistance to comprehensive immigration reform and public opinion’s inclination in its favor.

But all three points are spurious. A further amnesty would, if anything, probably incentivize further migration, just as Obama’s previous grant of legal status may well have done.

The public’s views on immigration are vaguely pro-legalization — but they’re also malleable, complicated and, amid the border crisis, trending rightward. And in any case we are a republic of laws, in which a House majority that defies public opinion is supposed to be turned out of office, not simply overruled by the executive.

What’s more, given that the Democrats controlled Congress just four years ago and conspicuously failed to pass immigration reform, it’s especially hard to see how Republican intransigence now somehow justifies domestic Caesarism.

But in political terms, there is a sordid sort of genius to the Obama strategy. The threat of a unilateral amnesty contributes to internal G.O.P. chaos on immigration strategy, chaos which can then be invoked (as the president did in a Friday news conference) to justify unilateral action. The impeachment predictions, meanwhile, help box Republicans in: If they howl — justifiably! — at executive overreach, the White House gets to say “look at the crazies — we told you they were out for blood.”

It’s only genius, however, if the nonconservative media — honorable liberals and evenhanded moderates alike — continue to accept the claim that immigration reform by fiat would just be politics as usual, and to analyze the idea strictly in terms of its political effects (on Latino turnout, Democratic fund-raising, G.O.P. internal strife).

This is the tone of the media coverage right now: The president may get the occasional rebuke for impeachment-baiting, but what the White House wants to do on immigration is assumed to be reasonable, legitimate, within normal political bounds.

It is not: It would be lawless, reckless, a leap into the antidemocratic dark.

And an American political class that lets this Rubicon be crossed without demurral will deserve to live with the consequences for the republic, in what remains of this presidency and in presidencies yet to come.