Politics is fickle, unfaithful and cruel.

Donald J. Trump scored big election victories in some of the nation’s most conservative congressional districts. And yet … many of those members of Congress representing those districts might be about to turn their guns on the president over his endorsement of what they call a “light” version of the Affordable Care Act.

The American Health Care Act has been put forward. The president is on board with the plan that offers tax credits for people seeking health insurance; it contains many of the features popular with the Affordable Care Act, which the AHCA is designed to replace.

Congress’s more conservative members, though, dislike it. They’re digging in. They’re fighting among themselves, not to mention with the president.

What to do? That’s the problem facing the master negotiator Donald John Trump as he tries to persuade the hard-core among his Republican brethren that the AHCA is worth approving and sending to his desk.

This is a tough sale to make with those among the GOP who just don’t want anything on the books that resembles — even in the slightest sense — something that was enacted at the behest of the former president, Barack Hussein Obama.

We’re likely now to see if the negotiator in chief is as good at this political game as he bragged about incessantly on his way to the White House.