Sanders responded by saying that, “In all likelihood, I will,” select a woman as a running mate. But he didn’t explicitly commit to it. “It is [about] making sure that we have a progressive woman — and there are progressive women out there — so my very strong tendencies would be to move in that direction.”

Biden and Sanders met Sunday night, with Biden looking to open up a commanding lead for the nomination Tuesday and with the nation struggling to contain the fast-moving coronavirus.

The debate comes amid escalating spread of the disease that is dramatically altering Americans’ way of life and the normal rhythms of a campaign. In-person rallies and fundraisers have gone digital. Staffers are working from home. And Sanders’ chances to shift the dynamic in his favor have become even more limited.

The Vermont senator and his allies view Sunday’s debate as his best chance to turn the race back in his favor, by presenting himself as the most capable challenger to President Donald Trump. Sanders set out to focus on his policy disagreements with Biden. Biden has sought to find some common ground with Sanders, agreeing to some concessions on progressive policies popular with most Democrats.

The key moments are below:

'This is much bigger than whether I’m the nominee'

A prolonged skirmish over their past votes over decades in Congress finally meandered to 2020.

“He's making it hard for me right now. I was trying to give him credit for things,” Biden joked, as he pledged again to back Sanders should he come back and win the Democratic nomination.

“I would hope that Bernie would do the same if I'm the nominee and encourage his supporters as well. It's bigger than either of us,” Biden said.

Sanders has said before that, he, too, would back the nominee. But the ire of some of his online supporters — and a nascent ‘Bernie or Bust’ movement that’s bubbled up — has seemingly necessitated his re-upping the promise.

“I hope to win the nomination,” Sanders said, “ but if I don't win the nomination, I and I think every other Democratic candidate is prepared to come together to do everything humanly possible to defeat Donald Trump” whom he called “the most dangerous president in the history of this country.”

Biden, Sanders answer day-one question on coronavirus

In the debate’s opening question, Biden and Sanders both laid out how they would handle the coronavirus if they were president — drawing contrasts with Trump’s own handling of the crisis.

Biden called for expanded testing and hospital capacity, as well as dealing with the economic fallout with interest-free loans for small businesses. He urged voters to go to his website, but didn’t drill into details of his plan.

Sanders, meanwhile, leaned on his signature issue: Medicare for All. He urged Americans that “when you get sick, if you have the virus, that will be paid for,” Sanders said. "If you lose your job, you will be made whole, you’re not going to lose your income.”

Biden took a brief shot at Trump’s handling of tests, but Sanders attacked Trump more explicitly: “Firstly, whether or not I’m president,w e have to shut this president up right now,” Sanders said. “Because he’s undermining the doctors and the scientists who are trying to help the American people. It is unacceptable for him to be blabbering un-factual information.”

'I wash my hands.'

Biden and Sanders — both in their 70s — are right in what health experts consider the danger zone for contracting coronavirus.

Both candidates noted that they’ve canceled their rallies and events, but they were also asked about what they have been doing, personally, to protect themselves from getting the virus.

“I'm not shaking hands. Joe and I did not shake hands,” Sanders said of their pre-debate elbow bump. Sanders said he’s also been careful about the people with whom he’s interacting.

“I'm using a lot of soap and hand sanitizers to make sure that I do not get the infection,” he added, in what was possibly the first time a presidential candidate has uttered those words.

Biden talked up his virtual town halls before turning to his own actions.

“I wash my hands. God knows how many times a day. I carry with me, in my bag outside here, hand sanitizer. I don't know how many times a day I use that. I make sure I don't touch my face and so on. I'm taking all the precautions we're telling everybody else to take.”

Biden swats down Medicare for all

Moments after Sanders cited his long-running support for Medicare for all, Biden pounced, arguing that solving the spread of coronavirus would not be aided by universal, government-run healthcare.

“With all due respect for Medicare for All, you have a single payer system in Italy. It doesn't work there. It has nothing to do with medicare for all. That would not solve the problem at all,” Biden said.

As Biden went on, Sanders looked down and shook his head. He contended that experts believe that the reason America was unprepared is because it doesn’t have a unified system. “We got thousands of private insurance plans,” Sanders said.

“That is not a system that is prepared to provide healthcare to all people. In a good year without the epidemic, we're losing up to 60,000 people who die every year because they don't get to a doctor on time. It's clear this crisis is only making a bad situation worse,” he added.

Biden shot back that a national crisis is no time for a back and forth on politics, adding that he laid out a plan to build on Obamacare, providing a public option.

“But regardless of whether my plan was in place or his, this is a crisis,” he said, ending the side debate over healthcare plans as part of a broader discussion about addressing coronavirus.

“This is like we are being attacked from abroad. This is something that is of great consequence. This is like a war. And in a war, you do whatever is needed to be done to take care of your people.”

Biden, Bernie battle it out over campaign finance

Biden and Sanders traded jabs over super PACs and campaign finance, prompting the former vice president to pull out an unusual brag — winning without money.

After a riff from Sanders about billionaires who “contribute money to political campaigns” and “who control the legislative agenda,” Biden jumped in to defend his contributions from big-money donors, touting his $44 average donation and noting: “Bernie outspent me — two, three, four, five, six to one. I didn’t have any money and I still won.”

Sanders said that Biden should get rid of his super PAC, Unite the Country, while Biden shot back that Sanders should “get rid of the nine super PACs” back him.

“I don’t have any super PACs,” Sanders said, attacking him for going negative on him.

Sanders mixes up ‘ebola’ and ‘coronavirus’

Biden is better-known as a gaffe machine, mixing up names and dates. But this time, Sanders, at least twice, referred to “ebola” instead of “coronavirus” in a prolonged exchange over how best to handle the current pandemic.

Sanders said the “ebola crisis, in my view, exposes the dysfunctionality of the health care system” and the “ebola crisis is, also, I think, exposing the cruelty and the unjustness of our economy.”

Within the same answer, Sanders caught himself, acknowledging his mistake. “Got ebola in my head,” he said.

Sanders verbal missteps came after an exchange about how the Obama administration handled the ebola crisis in 2014.

Coronavirus bailout?

Sanders voted against the Wall Street bank bailout. Biden, then the vice president, backed it.

A question about whether there should be a similar bailout for the economic effects of the deadly coronavirus pandemic quickly devolved into their past positions.

“To answer your question where we are right now,” Sanders said, “we need to stabilize the economy, but we can't repeat what we did in 2008.

“Joe voted for that,” Sanders elbowed. “I voted against it. Because we have got to do more than save the banks or the oil companies.”

Biden stood his ground, arguing had the banks gone under, “all those people would be in deep trouble. Deep, deep trouble.

“All those little folks, we would have gone out of business,” he continued. “They would find themselves in a position where they would lose everything they had in that bank. Whether it was $10 or $300 or a savings account. This was about saving an economy.”

Go to ‘the YouTube!’

Biden may have walked into a tailor-made hit by Sanders when he drubbed his fellow debater for running TV ads saying he’s opposed to social security. “It's a flat lie,” Biden shot at Sanders.

But Sanders brought receipts: He pointed to all the times the entitlement program was used as a bargaining chip for other legislation — and during times when budget-cutting and deficit reduction came up.

“All that I would say to the American people, go to the YouTube,” Sanders said. “It's all over the place. Joe said it many times. I'm surprised you can defend the change your mind on it, but you can't deny the reality.”

Biden wasn’t having it, but the line gave Sanders the opening he wanted on Social Security.