It’s not common for President Trump to face a critical questioner. Most of the television interviews he’s given as president have gone to Fox News or Fox Business, including a sprawling, generous one Tuesday morning.

On Tuesday night, though, he did face tough questioners. During a town hall hosted by ABC News, a number of Pennsylvania voters posed questions to the president, often focusing on subjects that he is generally not eager to talk about.

Julie Bard, for example, pressed Trump on his general indifference to wearing a mask during the coronavirus pandemic. And in doing so, she spurred a truly baffling and egregiously misinformed response — a response that was quite revealing, though not in the way Trump intended.

“The wearing of masks has proven to lessen the spread of covid,” Bard said, referring to covid-19, the disease caused by the novel coronavirus. “Why don’t you support a mandate for national mask-wearing? Why don’t you wear a mask more often?”

“Well, I do wear them when I have to and when I’m in hospitals and other locations,” Trump said. He’s made this claim before, but, to date, he’s been photographed wearing a mask only on a couple of occasions.

Then things got wild.

Answer 1: Former vice president Joe Biden didn’t do it either.

“But I will say this: They said at the Democrat convention they’re going to do a national mandate,” Trump said. They never did it because they’ve checked out and they didn’t do it. And a good question is, you ask why Joe Biden — they said, ‘We’re going to do a national mandate on masks.’ ”

“He’s called on all governors to have them,” interjected ABC News’s George Stephanopoulos, who moderated the town hall. “There’s a state responsibility.”

“Well, no, but he didn’t do it. I mean, he never did it,” Trump said.

Well, no, he didn’t. Because Joe Biden isn’t president and the Democratic Party isn’t in charge of setting federal policy. Biden did, as Stephanopoulos noted, call on governors to implement mask mandates a month ago. It wasn’t entirely successful, for fairly obvious reasons.

It’s not uncommon for Trump to offer a “what about Biden” response to difficult questions. He’s done so on the coronavirus repeatedly, including claiming (falsely) that Biden botched the handling of an influenza pandemic in 2009. Perhaps that’s what Trump was referring to in his response; there was no mask mandate at that time, largely because that virus was less deadly and less contagious.

But, then, Trump said that a mandate should have been implemented following the convention. So … who knows?

Answer 2: Some people don’t want to wear masks.

Trump then shifted gears.

“Now there is — by the way, a lot of people don’t want to wear masks,” he said. “There are a lot of people think the masks are not good. And there are a lot of people that as an example —”

“Who are those people?” Stephanopoulos asked.

“Well, I’ll tell you who those people are,” Trump replied.

One might have expected Trump at this point to elevate the various groups of people who have protested mask mandates. Embracing those protests would be tricky for Trump, given that he and his team have insisted that he’s following the science on the coronavirus and the science makes clear (as Bard said) that mask-wearing is a critical tool. But at least it would have made sense as a bit of political rhetoric.

Instead, Trump pointed to another group: “Waiters.”

“They come over and they serve you, and they have a mask,” Trump said. “And I saw it the other day where they were serving me. And they’re playing with the mask— I’m not blaming them. I’m just saying what happens. They’re playing with the mask. So the mask is over, and they’re touching it, and then they’re touching the plate. That can’t be good.”

As Trump has known since late January, a primary method of transmission for the virus is through the air. A waiter touching a plate with a bare hand is indeed not ideal, which is why waiters are generally instructed to wear gloves. But it’s hard to see how touching a mask and then a plate would be more risky than a waiter not wearing a mask at all, particular at an indoor dining establishment.

Trump’s made this assertion before, that touching a mask invalidates the utility of the mask. It doesn’t, as the science that Trump claims to follow makes very clear.

After the aside about waiters, Trump changed direction again, looping in the government’s top infectious-disease expert, Anthony S. Fauci.

Answer 3: The messaging on masks changed anyway.

“There are a lot of people,” Trump said — “if you look at Dr. Fauci’s original statement, you look at a lot of people, CDC, you look at a lot of people’s original statement. They said very strongly, George, ‘Don’t wear masks.’ Then all of a sudden they went to, ‘Wear masks.’ ”

It is true that guidance that originally emerged included recommendations against mask-wearing. In part, this was a function of some remaining uncertainty about how the virus spread most effectively. In part, it was also a function of need: Masks were in short supply, and what was available was needed by medical professionals. Recommending against civilians wearing high-quality masks meant more high-quality masks could be sent to hospitals facing a flood of infected patients.

In other words, the original suggestion that people not wear masks derived at least to some extent from the inability of the government to provide sufficient protective equipment to doctors and nurses.

On Feb. 29, Surgeon General Jerome Adams insisted that people stop buying masks, in part to preserve supplies for hospitals. This was more than a month after Trump was first briefed on the threat posed by the virus, a month during which, by the administration’s own admission, there was no effort to mandate a ramping up of production. In fact, the federal government was still shipping protective equipment to China well into that month.

Trump wrapped up his response.

“The concept of a mask is good,” he said, “but it also does — you’re constantly touching it. You’re touching your face. You’re touching plates. There are people that don’t think masks are good.”

One of those people, clearly, is President Trump.