When it comes to former President Donald Trump, loyalty is a one-way street.

Cross him even once and you’re toast.

Just the same, Idaho Gov. Brad Little must be terribly dejected that Trump would endorse Lt. Gov. Janice McGeachin in next spring’s GOP gubernatorial primary.

After all, Little has kissed the Trumpian ring repeatedly. When he showed up at the White House in 2017, he didn’t mind that the president got his name wrong. (It’s Brad, not Fred.)

And last week, Little traveled on the state dime to Florida, where he joined Trump at the America First Policy Institute Gala.

It was Little who signed on to Texas Attorney General Ken Paxton’s amicus brief attempting to steal the 2020 election for Trump, something Idaho Attorney General Lawrence Wasden refused to do.

It was Little who supported Trump’s anti-immigration stance, first by sending state troopers to Arizona and then by serving as a prop in Texas Gov. Greg Abbot’s photo-op.

And it was Little who has pushed back against virtually any statewide mandate that would have contained the COVID-19 surge in his state — even going so far as to try to block President Joe Biden’s vaccine mandates in the courts.

So what was Little’s crime?

He may have acted like Florida Gov. Ron DeSantis. But he talked too much like President Joe Biden’s chief medical adviser, Anthony Fauci, by urging Idahoans to get the shot.

And how must U.S. Sen. Jim Risch, R-Idaho, feel?

Not only is Little the epitome of the Idaho GOP establishment, but he’s a Risch ally. The senator’s wife, Vicki, served as Little’s campaign treasurer in the 2018 election.

Here Risch voted twice against Trump’s impeachment. He even snoozed through one Senate trial.

Never once in four years did Risch — even as chairman of the Foreign Relations Committee — find fault with any diplomatic or military decision Trump made.

At every turn, Risch shielded Secretary of State Mike Pompeo.

He called Special Counsel Robert Mueller’s investigation into Russian election interference on Trump’s behalf a “nothingburger.”

And when Trump took Russian President Vladimir Putin’s word over that of his own intelligence community at Helsinki, Finland, in 2018, Risch kept silent while the late Sen. John McCain called it “one of the most disgraceful performances by an American president in memory.”

All this sycophancy and what did Risch get in return?

Absolutely nothing.

Then there’s Idaho’s forgotten man, GOP gubernatorial hopeful Ammon Bundy.

He was Trump before Trump was cool.

It was Bundy who led an insurrection against the federal government — first in Bunkerville, Nev., in 2014 and then again at the Malheur National Wildlife Refuge near Burns, Ore., two years later. In August 2020, Bundy attacked the Idaho Statehouse.

Where do you think Trump got the idea of storming the U.S. Capitol on Jan. 6?

Bundy was way ahead of Trump by engaging in COVID-19 denial and he kept it up — fighting face mask mandates anywhere he could, whether it was the health department or a high school football game.

And talk about Trumpian bona fides. His endorsements include Trump acolyte Roger Stone and former Congressman Ron Paul.

What is Bundy? Chopped liver?

But the guy who must really be worried about now is Idaho Congressman Mike Simpson.

Simpson has done a lot of posturing lately, such as refusing to support a congressional subpoena against Trump’s personal Rasputin, Steve Bannon.

A veteran member of the House Appropriations Committee, Simpson didn’t kick up much of a fuss when Trump violated the congressional power of the purse and diverted Defense Department funds into his southern border fence project.

None of that is going to count with Trump.

If the former president doles out his endorsement to Simpson’s GOP primary rival, Idaho Falls attorney Bryan Smith, he’ll remember these gripes:

l Simpson called Trump “unfit” to be president in 2016.

l Simpson voted to certify Biden’s election — unlike his seatmate, Congressman Russ Fulcher, R-Idaho.

l Simpson was one of 35 House Republicans — and the only member of Idaho’s GOP congressional delegation — to support an independent commission to investigate the Capitol riot.

Of course, if total subservience is the price for Trump’s support, you’re left with two questions:

How did McGeachin win Trump’s endorsement?

And what is she willing to do to keep it? — M.T.