What did we learn from the Biden-Sanders debate? We asked four POLITICO campaign reporters — Marc Caputo, Holly Otterbein, Elena Schneider and David Siders — for their takeaways just before Democrats in Arizona, Florida, Illinois and Ohio vote on Tuesday.

Who won the debate?

Caputo: The 11th time was the charm for Biden, who looked like a completely different candidate onstage than in the prior debates. If Sanders wanted a debate to change the race’s trajectory, this wasn’t it. Biden benefited from low expectations heading into the night, but he over-performed by actually excelling in the debate, where he was relaxed, cogent and looked like what he is: the clear frontrunner in the Democratic race for president.

Schneider: Biden won the debate by making some news: pledging to pick a woman as his running mate. He also said he would nominate an African American woman to the Supreme Court. Those twin commitments will likely dominate headlines coming out of Sunday night’s debate, to the extent that non-virus-related news makes headlines right now.

It’s also a meaningful pledge, now that a historically diverse primary field — which included a record number of female presidential candidates — has narrowed to two white men in their 70s. Sanders, meanwhile, hedged on whether he would select a woman rather than pledging it outright, losing the chance to join Biden in the headlines as committing to a female VP. That’s a win for Biden.

Otterbein: Both candidates had decent debate performances, but Biden was ultimately the winner of the night because he is the frontrunner and he didn’t fall flat on his face.

Sanders’ strongest moments were when he took Biden to task over his climate change agenda and record of entertaining cuts to Social Security. And they were strong: Biden made misleading remarks about his past comments about Social Security, and Sanders at one point seemed to force him to acknowledge what he’d actually said. It’s the sort of exchange that could have made a big difference for Sanders, say, before South Carolina voted. But Sanders didn’t have a knockout moment — and at this late stage in the race, that’s likely what he needed.

Siders: Biden only had to keep it respectable to win this debate, with an imperative simply to avoid any lapse that might make his supporters in upcoming states think twice. That was a low bar to begin with, and Biden cleared it and then some.

He made news by pledging to pick a woman for vice president. He sidestepped Sanders’ most stinging critiques from a position of strength, inviting Sanders, for example, to “join me” in reforming campaign finance laws. And he cast himself as above the political fray — in an election he called “bigger than either of us.”

How did the coronavirus pandemic change the debate and the exchange between these two candidates?

Siders: It changed everything — but still, less than I’d expected. First, the changes: That elbow bump at the opening was not just cause for a chuckle, but a visceral reminder that these two candidates — and everyone else — are facing a common challenge together. Coronavirus shaped a more substantive health care debate than candidates have had in any of their previous meetings, and it exposed the differences between Biden’s emphasis on leadership in the moment versus Sanders’ emphasis on systemic change.

But given the gravity of the moment, I had not expected that the candidates could talk at length about any subject beyond the context of coronavirus, and that was wrong. This was also a substantive debate on issues ranging from Social Security to climate change and foreign policy. For whole stretches, a viewer could almost forget the pandemic shutting all of us inside.

Otterbein: There was no audience, and it was amazing. The networks should consider scrapping debate audiences forever.

Unfortunately — and even though the candidates started and ended the debate on the subject — coronavirus did not take up as much time as it could and should have, given how much it looks like it will upend our lives, economy and health care system.

Schneider: Like David said, coronavirus was a third player on the debate stage, but didn’t change much of the debate content. For the most part, Sanders and Biden agree on how to handle the crisis. They didn’t get too far into the weeds on how they’d do it, either. But the discussion of coronavirus served as more of a contrast with President Donald Trump than between the two Democratic presidential candidates.

Caputo: Coronavirus changed the debate for the better for Biden. In a small setting with people he knows, he was a totally different candidate facing off against Sanders. Unlike in past debates, Biden wasn’t nervous. He didn’t feel the need to shout. And he wasn’t heckled by progressive activists in the audience — because there wasn’t one.

On the substance, coronavirus led us back to more of the same: Sanders advocating for totally government-run health care and Biden calling for a public-private venture. In calling for Medicare for All, Sanders showed why he’s gained the trust of so many Democrats on health care by painstakingly pointing out the disparities in society. But the issue also gave a little lift early on to Biden, who came armed with a salient point that government-run health care does not guarantee an effective coronavirus response: “With all due respect to Medicare for All, you have a single-payer system in Italy. It doesn't work there,” Biden said.

Last week, Sanders challenged Biden to speak to the concerns of his base of young voters. How did that play out?

Otterbein: Biden has been signaling recently that he wants to reach out to Sanders' supporters, nodding to them in a recent speech. Hours before the debate, Biden's campaign also said he now supports making colleges tuition-free for families that earn less than $125,000. And the former VP’s team told me this weekend that he considers Sanders a “good friend and whose values and leadership he admires.”

But without the benefit of prepared remarks at the debate, Biden’s outreach to Sanders’ supporters wasn’t as crisp. At one point, he said Sanders is “making it hard for me” to open his arms to the Vermont senator’s backers. He also didn’t directly answer a question about his weakness with Latino voters, who have been siding with Sanders. Biden has a lot more work to do to achieve party unity.

Caputo: If Biden wanted this debate to allow him to attract more young voters, he did relatively little to address the concerns that those under 50 years old overwhelmingly approve of Sanders. Sure, Biden has adopted Sanders fully subsidized college tuition, but there was precious little here for young people.

Siders: Poorly, I think. Biden’s judgment that “people are looking for results, not a revolution,” as he said Sunday, is a message that moderate Democrats will find reassuring. But Sanders’ progressive base is looking for more. Yes, Biden adopted a proposal to make public colleges and universities tuition-free for students whose family incomes fall below $125,000 — an element of Sanders’ own platform.

But Biden was also visibly dismissive of Sanders’ calls for more systemic changes, and his smirking at Sanders did not go unnoticed. Discussing climate change, Sanders at one point said to Biden, “If you're laughing, you're missing the point.” And many of Sanders’ supporters will feel exactly the same.

Schneider: These are all good points, and I will just add that this was a quote from the candidate of young voters in this debate: “Go to the YouTube right now!” (to view clips of Biden on Social Security).

How will this debate affect the upcoming primaries?

Schneider: Not much. Sanders spent a solid amount of time Sunday night trying to pin Biden down on his votes in the Senate, from the Hyde Amendment to Simpson-Bowles deficit spending plan to the Iraq War. Much of it was about demonstrating places where Sanders has stayed true to his progressive bona fides and Biden hasn’t. At times, it got a bit hot. But Sanders didn’t go in for the kill, while Biden appeared steady.

Siders: I agree with Elena. It’s hard to see any impact on Tuesday’s primaries from a debate in which Biden, who is far ahead, performed well. Sanders got something out of this, which was the kind of substantive debate he has been craving. But it’s not clear he improved his electoral position at all.

Otterbein: We’ll see on Tuesday! Here’s what happens in Sanders' best-case scenario: Seniors unaware of Biden's past comments about Social Security will Google them and not turn out for him this week, and somewhat liberal voters who didn’t know or care about Biden's record or agenda on any number of issues — the Defense of Marriage Act, climate change, bankruptcy — will find out and flip to Sanders.

But it’s worth keeping in mind that Sanders’ campaign ran attack ads highlighting Biden’s comments on Social Security in the states that voted on March 10, and Biden swept most of them anyway. Sanders is down about 20 to 40 percentage points in the polls in the states that vote this week. That’s an uphill battle, to put it lightly.

Sanders said something about Biden tonight that I think was very telling: "I know your heart is in the right place, but this requires bold, dramatic action.” Sanders was talking about climate change, but he might as well have been talking about Biden’s entire campaign. If Biden wins the nomination as expected, the fact that Sanders believes his heart in the right place should ultimately make unifying the Democratic Party easier.

Caputo: Sanders could have laid into Biden far more than he did. That he held off was a sign that Sanders, subdued, is likely aware that polling shows him losing big time in the four states that vote Tuesday: Arizona, Florida, Illinois and Ohio. According to advisers, Sanders loathes Trump and ultimately would not want to harm Biden if he looks as if he’ll be the party’s nominee. And after tonight, it’s harder and harder to see Biden not leading the top of the ticket for Democrats in November.