Stop me if you’ve heard this one before. An aging reactionary decides to run for Senate in a red state, convinced that Trumpy populism has suddenly made him viable. He wins the primary, but thanks to his scandal baggage and staggering personal unlikability he goes on to bungle the general election, handing Democrats another seat.

Says Ben Shapiro, “With a bit of help from Steve Bannon, Republicans can turn the state blue!”

Oh, also? Arpaio’s 85 years old.

He talked to David Drucker about his upcoming candidacy in Arizona:

“I have a lot to offer. I’m a big supporter of President Trump,” Arpaio said. “I’m going to have to work hard; you don’t take anything for granted. But I would not being doing this if I thought that I could not win. I’m not here to get my name in the paper, I get that everyday, anyway.”…

To be sure, Arpaio’s reputation and close affiliation with Trump is virtually guaranteed to rev up a conservative base that had pushed the pragmatic Flake into retirement because of his feud with the president. That could work in his favor in a midterm, elections in which Republican turnout has tended to dominate. But in an election shaping up as challenging for the GOP, Arpaio’s candidacy could make nervous a party defending a 51-49 Senate majority…

Arpaio’s main offer to Arizonans: He would support Trump unflinchingly, should he win the nomination and defeat the likely Democratic nominee, Rep. Kyrsten Sinema. That’s not insignificant. Both Flake and McCain have a contentious relationship with the president, and he with them.

“I’ll be a loyal toady to the president” *is* a solid pitch in Republican primaries these days. Today’s announcement feels like a bolt from the blue but actually Arpaio’s been chattering about a Senate run for months. Back in August he talked about primarying Jeff Flake before Flake announced he wouldn’t run for reelection. At the time that felt like idle chatter by an elderly pol who’d enjoyed a turn in the presidential spotlight after Trump pardoned him over the summer and wanted to keep his name out there as he eased into retirement. But no, apparently he’s really going to do this.

Read the post from August if you missed it originally to see how many liabilities he has. There’s his age, of course, plus the fact that he was convicted of criminal contempt before Trump pardoned him. His incarceration practices are the stuff of dubious legend. His department overlooked hundreds of sex-crime cases, and meanwhile Maricopa County taxpayers paid out millions in lawsuit damages while he was sheriff for politically-motivated arrests of Arpaio’s critics. As a little decorative icing on the cake, he’s also a Birther. Last year, when Trump was winning the state narrowly, Arpaio was getting blown out in his reelection bid for sheriff by fed-up Maricopa County voters. Remember when I said yesterday that President Trump hasn’t been nearly as bad in office as NeverTrumpers feared he might be as a candidate? Arpaio really is that bad.

And of course he’s perfectly capable of winning a Republican primary.

But there’s a catch. The Arizona primary already has a fringy Bannon-style candidate, Kelli Ward. It also has a more mainstream candidate (or it will soon) in GOP Rep. Martha McSally. Until today things looked dicey for McSally: She’s nowhere near as unpopular as Flake but any establishmentarian will have a tough race in Arizona against a populist. Now, suddenly, there are two populists in the race and the new guy not only has much better name recognition than Ward but he’s closely linked in the public imagination with the president. It’s possible that Arpaio will bigfoot Ward by stealing her support; it’s also possible that he and Ward will divide the populist vote between them, ironically making it possible for McSally to win a three-way race. Unlike in Alabama, where the top two finishers advanced to a runoff after no one got an outright majority in the primary, Arizona is a first-past-the-post state. If McSally takes 34 percent of the vote to 33 percent each for Ward and Arpaio, she’s the nominee. Arpaio’s eleventh-hour bid might be a godsend to her by splintering the Breitbart contingent.

Which makes me wonder: Is he doing a favor here for the newly anti-Bannon Donald Trump, as a thank you for his pardon? McConnell may have persuaded Trump that Ward, who’s already been endorsed by Bannon, is quite capable of winning the primary and then blowing the general election just like Roy Moore did. Trump may want to endorse McSally instead but is nervous about choosing an establishmentarian over a populist again, as he did in Alabama. Solution: Call in a favor from Sheriff Joe, push him into the race to siphon off votes from Ward, and suddenly McSally’s path is clear. He’d be essentially gaming the primary to favor the establishment candidate without blowing his populist cred by formally endorsing her.

But that assumes that Arpaio would play ball. Would he? Like I say, he was gunning for Flake before Flake even retired. As grateful as he is to Trump for the pardon, an 85-year-old has better things to do than ride around the desert gladhanding people purely as a favor to a benefactor. He’s likely made the same calculation Roy Moore did: There’s a market for Trump-ish candidates in the “new” Republican Party and he’s capable of meeting the demand, certainly more so than Ward is. And who knows? Maybe Trump is excited at the thought of Arpaio running. Nothing would please the president more than to have a new senator who ran and won explicitly on the idea of being a rubber-stamp for his agenda. If Trump leaned on Ward to get out of the race and endorse Arpaio to form a “kook Voltron,” maybe with the promise of a job somewhere in the administration as a reward, Arpaio would suddenly have a real chance at the nomination. He’d probably get blitzed in the general election — Arizona isn’t as red as Alabama, which wasn’t red enough to elect Roy Moore — but Bannonites would consider that a price worth paying in trying to take over the party. If GOP voters won’t elect populists like Moore or Arpaio, the logic goes, better that a Democrat have the seat than some establishment Republican. The fewer establishmentarians in power the better. And if there are enough Democratic victories, some anti-populist Republican voters may finally decide to hold their noses and support populist nominees purely in the interest of expanding the GOP’s control in Congress.

If you doubt that Arpaio would be in deep trouble in the general election, remind yourself that just 21 percent of Arizonans supported Trump’s decision to pardon him. Fully 50 percent opposed it. Arpaio on the ballot would bring out Democrats in droves and would steer some centrist Republicans to either stay home or cross the aisle for the Democratic nominee — exactly what happened in Alabama. It’s a disaster in the making.