Geoff Diehl’s unconvincing political act

Lesley Becker/Globe staff/File

Lieutenant Columbo visited the Boston Globe on Monday. Not in person — that would be impossible — but certainly in impersonation.

By which I mean feigned befuddlement serving a strategic purpose. And the feigner? Geoff Diehl, frontrunner for the Republican US Senate nomination, a committed Trumpster posing as an above-the-partisan-fray everyman on the campaign trail.

Diehl says Massachusetts should have a full-time senator and laments that Elizabeth Warren can’t meet the state’s many needs, given her presidential ambitions. Plus, as a Republican, he’d have a seat at the current public policy table.

The distracted-incumbent charge is standard political fare, and hardly objectionable. Alas for Diehl, he just isn’t a talented enough thespian to pull off the persona of an almost-apolitical candidate motivated by a simple desire to put the state’s interests first. For starters, he has a hyper-partisan tell. See if you can pick it up. First clue: Asked to describe his adult evolution from left to right, Diehl spoke of growing up in a “Democrat household.” Second clue: In a recent forum, he said Warren wants to make herself “the face of the progressive left for the Democrat Party for 2020.”

Yes, it’s the hoary — and grammatically and nomenclaturally incorrect — substitution of Democrat for Democratic when referring to America’s other major political party.

Why does he use it?

“I don’t know if I’ve ever thought about it,” Diehl replied. So he had never known the other party’s real name? “I suppose,” he said. I returned to the matter when the editorial board interview concluded, expressing sardonic astonishment that Diehl had arrived at middle age without knowing the Democratic Party’s true name. It just wasn’t “a distinction” he had ever been aware of, Diehl said, adding: “I swear.”

Later, I asked whether he favored a ban on assault weapons. Shifting into studied Columbo-esque confusion, Diehl pretended to think I was asking about fully automatic weapons (think machine guns), the ownership of which is already highly regulated.

The current debate, of course, refers to semi-automatic rifles with certain military-assault-weapons-style features, like the AR-15. Oh, no, he wouldn’t ban those, Diehl replied, saying those weapons have the same “functionality” — one trigger pull, one round fired — as lots of other guns. That’s an artificial equivalence. Lethality, not functionality, is the signal difference between an AR-15 and, say, a semi-automatic deer rifle.

The discussion moved to closing the gun-show loophole; in 33 states, one can buy weapons from private sellers, at gun shows or elsewhere, without a federal background check. The candidate noted, correctly, that the loophole has been closed in Massachusetts. But what about other states? Diehl took another deep dive into dissimulation.

“You are asking a — theoretically — Massachusetts senator to decide how another state is going to handle this?” he said, seemingly astonished at the notion of a federal officeholder supporting a gun measure that extended beyond his/her state’s borders. No, he wouldn’t do that.

On to Republican rival Beth Lindstrom’s charge that Diehl is ducking primary debates.

True? Well, Diehl said, he had agreed to several debates as long as all three candidates participated, but after one such primary-season encounter, John Kingston “decided to withdraw from just about all of the other ones,” so he won’t go either.

So Diehl has essentially given Kingston a veto over whether he himself debates?

“I suppose.” Ah, leadership!

Anyway, Diehl added, he did plenty of candidate forums in the spring, acting as though he saw no difference between those forums and pre-primary media debates.

At about which point consultant Holly Robichaud let the calculating cat out of the expedient-excuses bag. “Beth Lindstrom is desperate,” she said. Translation: In classic cautious frontrunner style, Diehl will dodge rather than debate.

“By not debating, Geoff Diehl and John Kingston are depriving voters of the right to learn more about all the candidates,” says Lindstrom. Yes, indeed.

And particularly about those posing as something they aren’t.