Former Vice President Joe Biden is feeling the pressure of being the frontrunner in the 2020 Democratic primary, and his old habit of putting his foot in his mouth is already drawing fire.

But as his repeated verbal missteps trigger press scrutiny, some observers are firing back. “Lay off Joe Biden’s gaffes,” wrote Washington Post blogger Paul Waldman. There are more important things to worry about, and we shouldn’t feed a simplistic, pre-packaged media narrative about the former vice president, he argued.

Others have complained that, in light of Trump’s atrocious behavior and policies, any criticism of Biden’s comparatively minor gaffes is misguided.

While this is an understandable impulse, and coverage of gaffes can sometimes overtake substantive policy discussions, this criticism is mostly wrong. Talking about Biden’s gaffes is entirely fair game, and indeed, it may be an important discussion about his candidacy.

First, the comparison to Trump is just a non sequitur. Biden isn’t running against Trump right now, he’s running against 20 or so other Democrats. His strengths and weaknesses should be assessed relative to them, not to Trump. Whether Biden’s gaffes are getting disproportionate coverage compared to Trump’s is a discussion for the general campaign season.

That’s why Waldman’s defense of Biden falls flat. He wrote: “[We] make demands of politicians that no ordinary person would be able to satisfy. I can promise you that if I hired a team of people to follow you around for a week (let alone a year) recording every word that came out of your mouth, there would be some things you’d want to take back.”

Of course, there are nearly two dozen other Democrats running for president, and they, too, face scrutiny over their every public remark. And though this claim hasn’t been subjected to strict quantitative analysis, there doesn’t seem to be any real disagreement that Biden just objectively makes more embarrassing gaffes than the other candidates on a regular basis. Some have even criticized Biden for having a lighter campaign schedule than the other candidates, which would make his numerous gaffes even more worrying. Other candidates have their flaws — Sen. Bernie Sanders (I-VT) shouts excessively, Sen. Kamala Harris has made confusing and apparently contradictory claims about her own policy beliefs — but they just don’t seem as gaffe-prone.

This argument would be moot if gaffes were entirely meaningless, as Waldman argued. But at least in Biden’s case, they don’t always seem to be. They fall into two broad categories, as I see it: Gaffes that seem to indicate genuine confusion in the moment and gaffes that might reveal troubling prejudices.

Here are some of Biden’s recent “confused” gaffes:

“We choose truth over facts.”

Biden falsely claimed that he met with Parkland students as vice president after the school shooting in their town. The shooting happened after he was out of office.

He repeatedly referred to former British Prime Minister Theresa May as Margaret Thatcher.

He mangled a call for donations at the end of the Democratic debate.

Here are some of the potentially “revealing” gaffes:

“We have this notion that somehow if you’re poor, you cannot do it. Poor kids are just as bright, just as talented, as white kids,” Biden said. He then tried to correct himself: “Wealthy kids, black kids, Asian kids — no I really mean it, but think how we think about it.”

He called Sen. Harris — who is 54 years old — “kid” on the debate stage.

After boasting about his work with Southern segregationists — a misstep that was clearly too pre-planned to be classified as a “gaffe” — Biden lashed out when he was criticized, demanding Sen. Cory Booker “apologize” for asking him to apologize.

After being criticized for failing to respect women’s personal space, Biden placed his hands on a young girl’s shoulders at an event and told her she was “good-looking.”

He publicly joked about having “permission” to touch others at another event.

These are only his recent gaffes. In 2007, he condescendingly said of Barack Obama: “I mean, you got the first mainstream African-American who is articulate and bright and clean and a nice-looking guy.” That same year on the debate stage, he said:

I spent last summer going through the black sections of my town, holding rallies in parks, trying to get black men to understand it is not unmanly to wear a condom, getting women to understand they can say no, getting people in the position where testing matters. I got tested for AIDS. I know Barack got tested for AIDS.

Perhaps none of this on its own would be a major problem. People sometimes say odd things and get twisted into awkward phrasings without it meaning anything of significance. But the gaffes highlight two serious worries about a Biden presidency: Is he out of step with where the Democratic electorate is on race and gender? And does his age have an effect on his cognitive acuity?

And what makes these questions particularly important is that they both come up a lot in the discussions of Donald Trump. Not only would it be bad for Democrats to put forward a candidate who share some of Trump’s failings, but this choice would also make it more difficult for that candidate to attack the president on these grounds.

And let’s be clear: If Biden is the nominee, these issues will arise during the 2020 campaign. We might as well have the discussion about these questions now, and if it’s a devastating attack on him, then Biden deserves to be knocked out of the race. If he can laugh it off and convince voters it doesn’t matter, all the better. But one of the worries is that we knew this was coming. Biden himself has said he is a “gaffe machine.” And his previous presidential campaigns have been dismal failures. He knew this scrutiny was coming, and yet he seems to do little to avoid it. Whether he can overcome this personal obstacle is a big question.

Will it matter? It’s hard to say. Biden has charm and a large store of goodwill among the U.S. electorate. If he becomes the nominee, the gaffes issue will almost certainly be overplayed compared to its importance. But for now, it remains a genuine weakness of his. We’ll see if that makes a difference in the primary.