Right, right, “it’s just one poll.” But it isn’t. A few weeks ago, PPP had Flake’s approval rating in Arizona a breezy 18/63 overall, including 22/57 among Republicans. JMC Analytics, the firm responsible for this new survey, has him at 22/67 among Republicans. So intense is anti-Flake sentiment among Arizona GOPers in the wake of his feud with Trump that Kelli Ward, a comparatively weak candidate, has more than doubled him up here.

It’d be unusual for a youngish incumbent not to run for reelection in the belief that he can’t possibly win. U.S. senators are, by definition, good at running statewide races and Flake will have plenty of establishment financial support. He’s also a man on a mission: He believes he and other conservatarians are battling populists for the soul of the GOP so he’s probably less inclined than the average incumbent to surrender in the belief that it’s not worth fighting for his job. And yet, if the polling continues to look like this over the next few months, pressure on him to quit may grow even from some of his supporters. If he looks like a sure loser either in the primary or the general, better that he step aside and let the party nominate a solid Republican with a chance of winning.

By a three-to-one margin, Arizona GOPers want anyone but Flake. And yes, the Trump feud is most definitely hurting him. Trump enjoys a 78/22 approval rating among Arizona Republicans, not blockbuster but solid enough to cause a disfavored incumbent like Flake lots of pain. Remember that tweet Trump fired at him a few weeks ago? JMC asked GOPers if it made them more or less likely to support the incumbent:

Fifty-six percent of Arizona Republicans say Trump’s endorsement would make them more likely to back a candidate versus 19 percent who say it’d make them less likely. Who do you think is winning that battle for the GOP’s soul?

Serious question: How does this dynamic change for Flake? It’s unthinkable that he and Trump would reconcile. It’s possible, I guess, that Trump’s own popularity will tank so sharply among Republicans that there’ll be no political price for being on his bad side, but that’s also almost unthinkable. Even a president who’s bottomed out nationally will probably still draw majority approval among his own party. The only obvious prospect for a turnaround for Flake is if the congressional GOP starts passing all sorts of major base-pleasing legislation. At the moment, that also appears virtually unthinkable.

Trump wants this war, too. Even if Flake started voting with him more often (and he already votes with him on nearly everything, including the Senate health-care bill), the president’s populist inner circle is eager to make an example of an establishmentarian. Flake is a target of both passion, given his frequent criticism of Trump, and of opportunity, in light of his weakness in Arizona. Trump can send a message to the Senate GOP by trying to knock him out, pour encourager les autres:

“Most members of Congress are arrogant, and until a scalp is actually taken they are going to continue to be defiant,” longtime Trump friend Roger Stone told The Hill. “All he needs to do is punish one incumbent and I think you’d see a sea-change.”…

“He is 100 percent correct to go after McCain, Flake, Murkowksi,” said Sam Nunberg, who worked as an aide to Trump’s 2016 campaign.

Nunberg also expressed the hope that Trump would be able to engineer the defeat of Collins in a GOP primary if she sought to become Maine’s governor.

You know what I think: Flake could always drop out of the Senate race, regroup, then run a kamikaze conservatarian primary challenge to Trump in 2020. He wouldn’t win but he’d force a solid one-quarter to one-third of the party to think hard about casting a vote of no confidence in the president by supporting him instead.

Exit question: Why did Sarah Palin sell her home in Arizona? She’s a populist and a friend of POTUS. She would have been well positioned to challenge Flake herself this year.