Remember last summer when Trump half-jokingly threatened Heller’s Senate seat at a White House meeting because he was wavering on whether to vote with the GOP on repealing ObamaCare?

It’s been a long journey from there to Trump blowing up Heller’s Bannon-backed primary challenger in a tweet this afternoon.

This will annoy populists but it increases the GOP’s chances of holding the Senate next year. Good for POTUS for playing the odds smartly.

Message transmitted, message received:

Trump started twisting Tarkanian’s arm to quit the race last week, per Tark himself, but today was filing day in Nevada. Last chance to pull the trigger. I assume their tweets were coordinated, but you never know with this White House. It could be that Tark was on the fence and Trump decided to force the issue by making his preference publicly known. A shrewd play either way. I wonder if their conversations reached the point where Trump had to threaten him with a Heller endorsement in the primary if he didn’t back down.

Why not let Tarkanian take his chances with Heller? He led in two early polls of the race last fall, after all. The answer is that, given Tark’s electoral track record, the seat would have been likely to flip to Democrats no matter who emerged with the GOP nomination. Tarkanian famously has been running for office in Nevada for nearly 15 years and has yet to notch a general-election win. He ran for state Senate in 2004 and lost. He ran for secretary of state in 2006 and lost. He ran in the GOP Senate primary in 2010 and lost badly (to Sharron Angle, no less). He ran for Congress in 2012 and won the primary — only to lose by eight points to the Democrat. He ran for Congress again in 2016 and won the primary again, but lost a heartbreaker to another Democrat by less than 1.5 percent. Not terrific!

So imagine a Tark/Heller primary. Tarkanian would spend months bombing Heller with messages like — well, like this:

“Since the 2016 election, ‘DC Dean’ has actively attempted to undermine Donald Trump at every turn,” Tarkanian said in a statement last week. “Dean Heller has joined the Democrats, discredited FBI agents, the liberal mainstream media, and the Resist Trump movement in their attacks on the president.”

By the end of the race, populist and non-populist Republicans would be at each other’s throats. In a rare swing state won by Hillary, with the GOP incumbent already in peril, Heller would either lose the primary to a guy who can’t seem to get over the hump in November or win the primary and somehow have to convince all the Tark fans who hate establishment “cucks” to turn out for him. So Trump (and Mitch McConnell) played the odds: Clear the field for Heller, the centrist incumbent, by nudging the populist into a House race, no doubt with the promise of a presidential endorsement later if one is desired. That’s the safe play, especially with reporters sniffing around Tarkanian for allegedly misusing funds raised by his charity. Imagine Tark knocking off Heller in the primary only to be torpedoed by scandal in the general.

Exit question: Would Trump have made this move if Steve Bannon, who’s backed Tarkanian, were still in his good graces and a force on the populist right? At last check, Bannon was seen addressing the National Front in France and cooing over what a “virile,” well-dressed bro Benito Mussolini was. Maybe Trump would have blown up his candidate anyway.