If President Trump is a budding authoritarian, as his critics allege, one of the safeguards is Judge Neil Gorsuch.

For all that Trump has flouted norms and gotten off to an at-times amateurish start in the White House, his pick of Gorsuch was extremely normal and highly professional. The Gorsuch nomination is exactly what everyone should want from a President Trump, especially those who most fear and loathe him. Yet Trump’s fiercest opponents began denouncing Gorsuch in all the usual terms before Trump had even finished announcing him.

This is the dilemma for Democrats: Either Trump is a threat to the republic because he doesn’t appreciate the Constitution and is bound to violate it with excessive assertions of executive power, or Gorsuch is a threat to the republic because he has an overly punctilious view of the Constitution that entails, among other things, a dim view of executive overreach. Both can’t be true.

The knee-jerk opposition to Gor­such is a sign Democrats either haven’t thought through what they believe about Trump or are seriously conflicted. Do they want to throw out the rule book because Trump is a potential dictator, or do they want to play by the conventional rules stipulating they should fight a constitutionalist jurist because he won’t impose their progressive social agenda from the bench?

If they really believe Trump is as dangerous as they say, they should think of Gorsuch as the equivalent of Gen. James Mattis. He is a responsible choice from what they consider an irresponsible president, and they should embrace him on those grounds.

Presidents and Supreme Court justices are, of course, very different animals, but Gorsuch is the opposite of Trump.

If they hate Trump because he’s anti-intellectual, Gorsuch is a Harvard-educated lawyer who is widely admired for his acute analysis and writing.

If they worry Trump has shown little regard for the Bill of Rights, Gorsuch is a stickler for it, including the Fourth Amendment, which will be the foremost obstacle if Trump’s law-and-order agenda goes too far. If they fear federal power under Trump overawing the prerogatives of states and localities, Gorsuch is a devoted friend of federalism.

If they are anxious about the Trump executive branch trampling on the other branches of government, Gorsuch is on record calling the separation of powers “among the most important liberty-protecting devices of the constitutional design.”

The most relevant question for those who imagine themselves manning the barricades against authoritarian rule should be: Will Gorsuch vote against Trump when the president oversteps his bounds? His record suggests the answer is “yes,” and President Barack Obama’s former acting solicitor general, Neal Katyal, has written that Gorsuch has the necessary integrity and independence.

So why won’t Democrats follow the logic of their anti-Trump reasoning and support Gorsuch?

First, there is sheer partisanship. They believe the Scalia seat has been “stolen” from them because Senate Republicans refused to act on the nomination of Merrick Garland. It was entirely in their power to reverse this act of alleged theft by winning the presidential election or the Senate majority last fall — but they came up empty.

Second, there is the fact that Democrats don’t truly oppose Trump on procedural or constitutional grounds, and so have no use for the likes of Gorsuch. They are happy with overreaching unilateral executive rule, so long as it produces results they like.

Liberals didn’t object to Obama’s executive orders unilaterally rewriting immigration law; they didn’t recoil when he was repeatedly shot down 9-0 by the Supreme Court; they applauded his moves to impose federal supervision of select police forces around the country. There is no principle about the limits of the government at stake here, only the question whether it is liberal or populist/conservative policies being imposed.

Third, the left cares about social issues more than anything else, particularly the judicial imposition of the current abortion regime. If Gorsuch isn’t on board, it doesn’t make a difference whether he will be a presumptive check on the president or not.

Finally, Democrats are getting sucked into the politics of the primal scream. They are heading toward all-out war against Trump, in which case all that matters about Gorsuch is that he’s associated with the president.

The best way for Trump to overcome this unhinged opposition is to make choices as sound as he did with Gorsuch: He is an unassailable pick being assailed by people who profess to yearn for sobriety and traditional norms, even as they reject both themselves.