Conservative Republicans should have known what they were getting when they stood firmly behind their party’s presidential nominee in 2016.

They were backing a guy who didn’t understand them, didn’t understand how to legislate, didn’t grasp the degree to which they would run through brick walls to get their way.

So, when Donald Trump hooked up with congressional GOP leaders — comprising a few moderates here and there along with some notable conservatives — on a cobbled-together health care overhaul, the Freedom Caucus bolted.

The caucus opposed the American Health Care Act. It spoke as one. The president couldn’t deliver.

Don’t get me wrong. I don’t think the Affordable Care Act should be repealed. It does kind of make me chuckle, too, to see the president get his head handed to him by a group of zealots who want the ACA tossed into the crapper.

But now the president has all but declared war against the Freedom Caucus. I believe this open warfare might doom whatever passes for Trump’s legislative agenda for, oh, the foreseeable future.

Trump is a RINO to many conservatives anyway. RINO, of course, means Republican In Name Only and it’s not altogether clear what precisely informs any public policy that pops into the president’s noggin.

The biggest surprise to me was that conservatives would stand with this candidate to begin with, given his bizarre personal marital history, his acknowledged groping of women, the manner in which he spoke to — and about — his more conservative GOP primary opponents. Whenever I hear Trump talk openly about matters important to social conservatives, one word keeps popping into my head: panderer.

Thus, I shouldn’t be surprised that the president would stake his agenda on cooperation with anyone other than the Freedom Caucus.

He’s not one of them. They certainly do not follow his lead.

The battle, therefore, is joined.