I mean, by outward appearances, an almost canine loyalty to the president is the guy’s defining characteristic.

Asking if Mike Pence is loyal is like asking if the Pope is Catholic. Or if the Pope is in deep denial about the severity of the Church’s sex-abuse crisis. The question answers itself.

So why is Trump allegedly asking so often lately?

Mr. Trump has repeated the question so many times that he has alarmed some of his advisers. The president has not openly suggested dropping Mr. Pence from the ticket and picking another running mate, but the advisers say those kinds of questions usually indicate that he has grown irritated with someone…

But some Trump advisers, primarily outside the White House, have suggested to him that while Mr. Pence remains loyal, he may have used up his utility. These advisers argue that Mr. Trump has forged his own relationship with evangelical voters, and that what he might benefit from more is a running mate who could help him with women voters, who disapprove of him in large numbers.

Others close to the president believe that asking about Mr. Pence’s loyalty is a proxy for asking about whether the vice president’s chief of staff, Nick Ayers, is trustworthy. Mr. Trump has been considering making Mr. Ayers the White House chief of staff to replace John F. Kelly, the retired Marine general — a decision several White House officials say has been with the encouragement of his adult children. But the president has put off making a decision for now.

Why might Trump be questioning his loyalty? Fun theories are kicking around the Intertubes this afternoon.

1. The Times claims that some outside advisors are nudging him to drop Pence from the ticket in 2020 and replace him with, er, Nikki Haley, who’s every inch as ambitious as Pence is and has a much more stronger base of support within the party independent of Trump than Pence does. Haley’s even been accused of authoring the famous anonymous NYT op-ed a few months ago by an administration insider who had joined the “Resistance.” If loyalty is what he’s worried about, Haley’s the last person Trump would dump Pence for. If, on the other hand, electability in 2020 is what he’s worried about, a Trump/Haley ticket would be an interesting proposition for the suburbanites who deserted the GOP in state after state last Tuesday. In fact, apart from Haley, I’m not sure there’s another woman in the GOP prominent enough to plausibly muscle Pence aside for a spot on the ticket. Maybe Trump’s loyalty inquiries about Pence were inspired by the pro-Haley faction whispering in his ear, trying to plant a seed of doubt in Trump’s mind in hopes that he’d get paranoid and dump Pence for their favorite.

2. Could it be a Mueller thing? Could Mike Pence quietly be working against the president on Russiagate? By his own admission, Trump’s been busy lately responding to written questions from Mueller’s office. All sorts of people have observed over the past week that he seems glum, distracted, and more irritable than usual. One theory is that something’s going on behind the scenes with the Russia probe that has Trump worried. Maybe something in the questions Mueller sent him touched on something which Trump thinks only Pence and very few others might be in a position to know. Or, worst-case scenario, maybe Trump has reason to believe that Mueller — or the incoming Democratic majority — is about to uncover something about him that might imperil his presidency. In which case he needs to know up front: How loyal is Pence? If Trump ends up in a fight for his political life, would Pence stand with him or is there any chance he might try to capitalize on Trump’s distress by pushing him out somehow? Remember, there have been claims in the past that members of his cabinet have whispered about the 25th Amendment.

3. As the Times itself notes, rumors have been flying for days that John Kelly’s about to be pushed out and replaced by Pence’s ambitious young chief of staff, Nick Ayers. Here’s how Gabriel Sherman described the Ayers situation a few days ago:

Ayers, politically gifted but conspicuously ambitious, and with questionable loyalty to Trump, would bring his own baggage to the job. “Half the West Wing told me they’d walk out,” a Republican close to the White House said. A Washington Post correspondent reported that Kellyanne Conway told friends she’d quit if Ayers got the job. (Conway told me that the suggestion was “silly.”)

Ayers is a creature of the GOP establishment, having worked for the Republican Governors Association and having helped get Reince Priebus chosen as RNC chairman. Importantly, he worked for Pence in his reelection bid for Indiana governor two years ago and then lobbied to have Pence added to the ticket as VP. That is, he was Team Pence before he was Team Trump. POTUS might be thinking about that and about and wondering if making Ayers his new chief would be inviting a fox into the henhouse, particularly if the White House is about to end up under siege from Mueller and the Democrats. This theory from lefty Melissa McEwan appeals to my appetite for intrigue:

I have long said that I believe Pence has been working with the FBI since the campaign and with Mueller since he started his investigation, and I believe it still. And, as I have said many times, to really understand Mike Pence, you have to understand that he has wanted to be president virtually his entire life, and he will do anything to get it. (Besides being a decent human being with good policy, obviously.)

All of which means: Pence knows if Trump goes down in an election loss in 2020, his own last, best shot at the presidency goes down with it — meaning his best bet is to make sure that Trump goes down via resignation or impeachment. Even election rigging can’t help someone who doesn’t get nominated.

Pence isn’t really loyal, notes McEwan, which is true. The guy didn’t even endorse Trump before the Indiana primary in 2016, when POTUS was on the doorstep of locking up the nomination. Pence is a movement conservative and an evangelical, both of which Trump emphatically isn’t. But you’re not going to land the GOP nomination for president anymore by running as those things. The base wants a Trumpist and Pence knows it, so he’s spent the last two years doing his best to ingratiate himself to them. The solution: Devout loyalty to their hero, at least in public. Trumpers might never love him or accept him as one of their own, but until Tom Cotton gets a higher-profile job there’s no big-name nationalist alternative to Pence as Trump’s logical heir. So loyalty is the way to go, unless and until it looks like the Trump ship is going down, at which point Pence’s ambitions will require him to be disloyal. Trumpers would hate him for that, but the shining lesson of 2016 is that Republican voters are capable of forgiving a lot in a candidate when the alternative is electing a Democrat. And virtually all of the top tier of Democrats in 2020 are solid leftists, making the “lesser of two evils” logic even starker for righties. Who are you going to vote for, the right-wing weasel who wouldn’t stand by Trump under fire — or Elizabeth Warren?

Maybe that’s what Trump is worried about. His next two years will be turbulent, his VP is highly ambitious and not ideologically like-minded, his administration is staffed with people who’d be more comfortable with a President Pence than with a President Trump. Is Mike Pence loyal? is an increasingly important question.