On Tuesday, it was Kamala Harris, who just this summer had so humiliated Biden on the national debate stage that analysts questioned whether black supporters would ditch the former vice president in droves. Instead, as Biden exited an event in north central Iowa, reporters shouted questions at him about whether he’d still consider Harris as his running mate.

Earlier this week, Montana Gov. Steve Bullock, who joined the primary with the promise of capturing moderate voters who believed Biden was too old and out of touch, folded his presidential campaign.

The chest-thumping two months before the Feb. 3 caucuses is a risky approach for Biden, given the fluidity of the race, especially in Iowa, where Biden has steadily lost ground in polling since January. And historically, Iowa voters have demonstrated their willingness to make last-minute shifts, falling away from a safe bet or getting behind a relative unknown, just before the caucuses.

But despite his wobbly debate performances, lackluster fundraising and verbal mishaps, Biden is still standing. And nationally, he’s still leading in the polls.

“Biden has every reason to be confident about his positioning. He’s been durable and somewhat Teflon,” said Andrew Gillum, the Florida Democrat who fell just short of winning the governorship last year. “Probably feels even better with Harris out. Now the Veepstakes can begin.”

Addressing worries about his war chest, Biden’s campaign manager Greg Schultz on Monday tweeted that the campaign had raised more money in October and November than it did in all of the last quarter. Still, Biden has lagged Buttigieg, Bernie Sanders and Warren in fundraising; the latter two especially have built out much larger online grassroots operations than Biden.

“Biden’s been in the race since April, and despite ups and downs, and many gaffes and missteps, and attacks by many of the other candidates, he’s still standing as the overall frontrunner,” said Garry South, a Democratic political consultant from California who long expressed doubts about his home state senator’s presidential bid. “So there’s something to crow about, I would say.”

At least some of Biden’s self-assuredness is about Medicare for All. Biden noted in an interview Monday that Democrats doubted his candidacy early on because he would not embrace a complete remake of the health care system. Now, he said, other candidates are paying a price in the polls for embracing Medicare for All, and moving toward his plan.

In the interview on his campaign bus, Biden quickly objected when he was asked to lay out his path in Iowa given his enthusiasm gap with other candidates, including Warren.

“You don’t see that [enthusiasm] with Warren, stop kidding a kidder, okay? Come on, man. Give me a break,” Biden said. At first Biden said the enthusiasm for Warren was lacking in Iowa but then he added: “And everywhere, look at the polling everywhere. Tell me. Tell me, where this great enthusiasm has manifested itself?”

Biden partly walked back those remarks after an event in Mason City on Tuesday.

“I think there is enthusiasm for her,” Biden said. “The point I was making was that I don’t think the bulk of the enthusiasm in the Democratic Party is for Medicare for All. There is enthusiasm for people who support that. … I don’t think that is where the center of the party is, or the left or the right of the party is."

Another looming threat for Biden is billionaire Michael Bloomberg, who in a matter of weeks dumped nearly $60 million on television.

When asked on Monday how he felt about Bloomberg’s candidacy, and the possibility that he would spend hundreds of millions of dollars of his own money, Biden essentially shrugged it off.

“Look at the other billionaire, what has he spent, $35 million bucks? Ok, well, show me what it’s done,” Biden said, referring to billionaire businessman Tom Steyer, who is in the race and just qualified for the December debate. “You can’t sit and say if someone’s going to spend, $200 -- $300 — up to a billion of their own money, you can’t say don’t worry about that at all. But … we’ll see. I don’t discount it, but I don’t spend any time thinking about it. Nothing I can do about that. Zero.”

Biden’s confidence also rests on his position in South Carolina and a raft of Southern Super Tuesday states that include more diverse populations, including more conservative Democrats. To that end, Biden said Monday if he faltered in Iowa, he could still win the nomination. But if he won Iowa, Biden argued he’d be almost unstoppable.

And Biden said he doesn’t see anyone even close to him in South Carolina polling who could suddenly surge even if they won Iowa.

“There is no one else who is in a position to all of a sudden to do what Barack was able to do," he said. "I think even if we didn’t do well in Iowa, we’re still way in the game in terms of where we are on Super Tuesday and where we’ll be in South Carolina and Nevada. I feel confident about those two and I don’t see something fundamentally shifting."

"The reason why it’s so important in Iowa — if the reverse happened, if I were to come in here and win this … and then do well in New Hampshire. Then, what stops it?”

Even a now-former Harris campaign aide privately expressed that Biden was more resilient than her team predicted.

“Look, Biden is a lot tougher than all of us gave credit for,” the aide said. “And the fact is that the polls don’t lie. He’s got solid support from the [African-American] community. Now is he unbeatable? No. But I don’t see Cory [Booker] or Deval [Patrick] making it or significantly cutting into his support with African Americans.”