If Wednesday night’s climate change town hall is any indication, Joe Biden could use some Windex for his glass jaw. But his supporters are perfectly willing to sweep up the pieces and write off his not-so-infrequent missteps.

The former vice president has been a candidate for the highest office in the land—officially or unofficially—for all of my adult life. His affable, self-deprecating style is an attractive lure for voters who see him as the kind of candidate they’d most like to have over for Sunday dinner.

Biden is equally at ease on a crowded Acela Express commuter train, in an Iowa cornfield, or the pulpit of a black church. While some politicos might have difficulty finding their footing, the former senator from Delaware can hum with the Methodists and holler with the Baptists.

There are folks who would pay good money for a bottle of his charisma. And Biden knows the business of Washington. He knows how things work, and that’s saying something in the age of Donald Trump, who has taken to drawing on a weather forecast with a Sharpie.

But despite the depth of his career as a statesman, and keen understanding of the intricacies of public policy formulation, he is perhaps best known for his uncanny ability to botch a stump speech. Biden is known for regaling audiences with highly emotive, deeply affecting personal stories, but his everyman persona is sometimes mired in gaffes, or bigger errors, that betray a lack of message discipline.

Political pundits and prognosticators from across the ideological spectrum have been making hay of Biden’s blunders since Joseph the Carpenter and his wife Mary set out to find a decent motel room in the Judean outback. Some have openly groused about his ability to survive the highly fractured primary or believe he might be sucking the air out of the room for better candidates. What they should not doubt, however, is the Biden base.

A pragmatic, deeply loyal voting bloc, Biden supporters tend to dismiss what they believe are honest slips of the tongue. While cable news politicos and social media influencers are busy vetting every public statement—by every candidate—and fact-checking in real-time, voters are tuned in to something else. How does he make me feel? More than anything, voters want to know who is on their side.

Biden is indisputably the Democratic frontrunner, despite a raft of mediocre to bad performances—and his support has not waned. His poll numbers are as reliable as the sunrise over Pennsylvania Avenue.

Even so, the Biden record is rife with missed opportunities. It seems, however, that everybody except the candidate himself understands that. At times appearing ill-prepared to reckon with his own legislative votes, public writings or speeches, he has stumbled and sometimes flashed a smile to mask the impact of the hit. But, if Kamala Harris was out to shake his support among African-American voters by taking him to task over cozying up to known segregationists, it didn’t work.

The same will hold true now as pollsters begin weighing what, if any, effect an audience question during CNN’s climate change debate will have. Northwestern doctoral student and Bernie Sanders supporter Isaac Larkin “chin-checked” him over a high rolling fundraiser and former Biden adviser connected to the fossil fuel industry.

“How can we trust you to hold these corporations accountable when you are holding a high-dollar fundraiser held by Andrew Goldman, a fossil fuel executive?” Larkin asked.

The Sanders campaign took to social media, accusing Biden of violating his campaign pledge to ban such contributions. That Goldman is not an actual fossil fuel executive and has been closely allied as a campaign staffer and Senate adviser mattered little because Biden never truly pushed back. His head-scratching response: “I will not in any way accept his help” if it turns out his campaign vetting operation made the wrong call.

It all made for good political theatre. In the end, though, it’s unlikely to matter. Biden has been on the national public stage for over three decades and, in that time, voters feel like they’ve gotten to know him. Rank-and-file Democrats—including a significant share of African-Americans—aren’t going anywhere, anytime soon. She’s making good work of it, but it will be tough for Elizabeth Warren to peel off middle-aged civil servants, teachers and others who are loyal to Biden, and even harder for Bernie Sanders, who comes to the race with his own hardened base of support, but whom Democrats don’t always embrace as one of their own.

Even if they don’t always trust Biden not to say something embarrassing, they tend to trust his intentions. If he turns in a lackluster performance, they are more likely to turn a blind eye than switch horses mid-stream. While his linguistically intimate style comes with risks, it has created a reservoir of goodwill among some of the party’s most reliable voters. They are accustomed to and forgiving of Biden’s blooper reel.

Certainly, there are substantive questions he should face about the 1994 federal crime bill, his handiwork on so-called welfare reform, and the confirmation of Clarence Thomas. No one alive at the time can forget how Anita Hill was treated. There are those, however, who are—for better or worse—willing to look beyond it.

“ Biden’s proverbial fire wall of centrist, so-called main line Democrats have historically shown themselves both pragmatic and protective. ”

And when all else fails, Biden and his supporters have been known to point to the 44th president—Barack Obama—like the Good Housekeeping Seal of Approval.

The 2008 campaign was fueled by Obama’s ability to “transcend the racial and economic contradictions of American history through inspiring optimism and persuasive rhetoric,” as Ted Sheinman writes in The New Republic. Biden hasn’t been able to match Obama’s penchant for inspiring rally-goers to raucous rounds of applause and impromptu chants of “Yes, we can!”

But his selection as running mate and service as Obama’s “wing man” is endorsement enough in some quarters of the party. For them, it’s enough to look over his seeming lack of preparation for a televised climate change forum.

Biden’s proverbial firewall of centrist, so-called main line Democrats have historically shown themselves both pragmatic and protective. It held up for Hilary Clinton in 2016, despite a Sanders onslaught, but faltered in 2008 with the rise of Obama. Will they continue to circle the wagons around Cousin Joe this time? Likely. But, he’ll need every single one of them to see the other side of Super Tuesday.

Biden currently enjoys a double-digit lead in national polls. That’s dandy when it comes to attracting money and volunteers. But losing Iowa, New Hampshire or both—real possibilities—could be damaging to the “electability” question. If the Biden firewall actually falters, it won’t be because he got caught flat-footed in another debate and his supporters scattered. They’ve come to expect his mediocrity. If Biden loses, it won’t be because the wall crumbled. It’ll because the remaining 65 percent of Democratic primary voters who aren’t currently supporting him coalesced behind somebody else.

Even then, Biden loyalists can be expected to stand their ground.