Just something I’ve been thinking about since the president dropped this tweet early this morning.

https://twitter.com/realDonaldTrump/status/898136462385979392

Of all the ways he could try to take out Flake to punish him for his endless criticism, touting Ward is the oddest. McCain beat her handily in the primary last year, after all. And she has a habit of wandering into needless controversies, from holding a hearing on, um, chemtrails to publicly calling on McCain after his cancer diagnosis to hurry up and step down in hopes that she might be appointed to his seat. Even stranger, the White House has been vetting more formidable challengers to Flake over the last few months. He’s in a lot of trouble in Arizona; a serious opponent really might be able to knock him off in a primary. Having Ward as an opponent would be his best bet for survival. And if Ward beat him, she might be easy pickings for a credible Democrat like Kyrsten Sinema in the general.

So why is Trump pushing her instead of one of the White House’s favored candidates, knowing that any presidential hype for Ward makes it that much harder for a second primary challenger to Flake to get traction? Who knows?

Trump aides were taken aback by the tweet. Many of them are deeply skeptical about Ward’s ability to defeat Flake…

The White House has met with two other prospective Flake opponents, Arizona state treasurer Jeff DeWit, who was a top official on Trump’s campaign, and former state GOP chairman Robert Graham…

People close to DeWit and Graham were also surprised by the Thursday tweet and said the two prospective candidates had been given no advance warning that the president would be weighing in on Ward’s behalf. DeWit and Graham had been waiting for weeks for word from the White House about where the president stood and whom he wanted to support.

Ward does have a Trumpy vibe to her and more importantly she (or her Super PAC) has $300,000 of Trump backer Robert Mercer’s money. Maybe Trumpworld really is going all-in on her despite the hard lessons Republicans have learned about nominating “colorful” candidates like Todd Akin, Richard Mourdock, and Christine O’Donnell in otherwise winnable Senate races. McConnell’s going to have an aneurysm at the thought of losing Flake and seeing him replaced by either a populist loose cannon in the Trump mold or a Democrat.

But that’s one of the reasons why Flake primarying Trump in 2020 as revenge would be fascinating. A Kasich primary challenge would feel stale by comparison after 2016. He’d run from the center, not from Trump’s right, which would be intriguing to many Republicans but not to the sort of conservatives and populists who populate right-wing media. I think Kasich would also convince himself that he has a small chance of winning, which he wouldn’t have unless Trump grew so radioactive politically that he shouldn’t even bother trying to get reelected. Flake has none of those problems. He would run from the conservatarian right (except on immigration, notably, where he’s more libertarian); he’d be a fresh face to most of the national Republican primary electorate; and he would understand up front that he had no chance of winning but was running merely as an evangelist for conservative principle. He’s soft-spoken and personally appealing too whereas Kasich is frequently abrasive.

Maybe most importantly, Flake has a lot of friends in the U.S. Senate. Normally you wouldn’t dream of senators from a sitting president’s party supporting one of their own in a primary challenge to him, but given the trajectory Trump is on, anything’s possible by 2020. He’s attacked McConnell recently, he attacked Flake this morning, and he took a shot at his frenemy Lindsey Graham on Twitter over Charlottesville. A lot of ideological conservatives in Congress would have a hard time backing Trump over a true believer like Flake even though it’s what the party’s (short-term) interests call for. Flake seems to relish the true believer role too: The crux of his critique of Trump is that the president’s neither a conservative nor a decent person. He’s not going to win a Republican primary with that argument but he might do better than you think (remember, fewer than 70 percent of GOPers supported Trump on Charlottesville this weekend). And he could inflict some pain on Trump that lingers into the general election. Candidates like Marco Rubio made the case last year in the primaries that Trump was grossly unfit for office but (a) that was a pure hypothetical and (b) it was undermined when Rubio himself embraced Trump in the general. Flake will have four years of data by 2020 that he can use to try to make the same case. And no matter what happens, it’s almost impossible to imagine him endorsing Trump afterward the way Rubio did.

Win or lose in 2018, Flake could pay Trump back two years later. If he’s out of office, he’ll have plenty of time to prepare. If he’s still in office, he’ll have already faced down the dragon and survived and won’t have to worry about Arizona voters again until 2024.

Eh, who are we kidding. Mike Pence is probably going to be the nominee. Right, Democrats? Exit question: Is Trump going to promote Ward again at his rally in Phoenix next week? Or will the festivities be limited to pardoning Joe Arpaio?