I carry no brief for President Trump. Quite the contrary. Last year, I chaired the "Republicans for Her 2016 PAC" because I believed Trump temperamentally unfit to be president of the United States.

But Trump will not be president forever, and the presidency, and our civil society, now seems as much threatened in the long run by the extremism of "the resistance" as by that which it resists.

This is notably true in watching the intellectual (and moral) gymnastics on the left in opposition to anything and everything Trump says about world affairs, as distinct from principled criticism of particularly objectionable pieces of Trump foreign policy.

Take the new-found belligerence of Democrats toward Russia, after a century of almost unbroken Democratic dovishness toward Russia as compared with GOP hawkishness.

Take the horror toward what was taken (credibly) as an implied threat by the president of the possible use of nuclear weapons as a deterrent against the actually, already, and repeatedly threatened use by the North Koreans of nuclear weapons against our county and our allies, when it has been the unbroken policy of the United States — every president in the nuclear age — to reserve the right to use nuclear weapons, including the first use of nuclear weapons.

And at a time when one's stand on policy is determined more by where one stands politically than on any set of consistent principles, consider also the hysteria over the president's statement that there could be a U.S. military option in response to the humanitarian crisis in Venezuela.

Now, let's stipulate that the president didn't mean it. Let's further agree that the commentators reacting as if this statement was a completely aberrant and abhorrent way of thinking knew he didn't mean it.

Still, this questionably loyal opposition acted as if this statement was real policy and that such a real policy would be beyond the pale of reason, decency, and history.

Huh?

In just the last half century, in continued fulfillment of the Monroe Doctrine — America's oldest foreign policy premise — the United States invaded the Dominican Republic (under LBJ), Grenada (under Reagan), Panama (under George H.W. Bush), and Haiti (under Clinton).

None of these circumstances provided fundamentally better justification for these U.S. actions by presidents of both parties than would be the case if the United States intervened today on behalf of a restoration of democracy, and an adequate food supply, for the suffering people of Venezuela.

Beyond the obvious but completely and deliberately-ignored hemispheric precedents, the irony of the outrage on the left about Trump's comment on Venezuela is that it was not long ago at all — in the wake of the disastrous U.S. non-involvement in the Rwandan genocide and the successful, if belated, U.S. involvement in ending genocide in the Balkans — that the left was coalescing around a doctrine of "humanitarian intervention," particularly during the slaughter in Darfur.

Indeed, perhaps the most beloved modern liberal president, the fictional one on TV's The West Wing, made a declaration of the right and responsibility of the United States to intervene militarily around the world for humanitarian reasons the centerpiece of his feigned second inauguration.

It's more than fine, of course, for people to change their minds for good reasons. It's more than fine, of course, to apply a broad principle of policy differently in apparently similar situations if there are more subtle differences beneath the surface or other countervailing principles more important in a particular case.

But the opposition to Trump on his Venezuela musing was about none of this. It was about being, saying, and doing the opposite from him on all things at all times, even when he takes a position with which critics might otherwise agree if taken by someone else.

There were too many Republicans who treated President Barack Obama that way. Now, essentially all Democrats are treating Trump like this.

If the only principle about which we Americans can be consistent is undercutting our political opponents, whether on matters domestic or international, do we have any principles remaining at all?

Craig Snyder is president and CEO of the World Affairs Council of Philadelphia. csnyder@wacphila.org