Live Updates Ahead of Sunday’s Democratic Debate

Mr. Biden, they said, would crumble in a one-on-one discussion with Mr. Sanders. Democrats across the country, they said, would see the wisdom of the Sanders way and turn to him as the right choice to defeat President Trump. All it would take is Mr. Sanders delivering a lacerating dissection of Mr. Biden’s record and plans.

There’s no evidence Mr. Sanders is willing to do that.

Instead the Vermont senator, his path to the presidential nomination nearly closed off, has continued presenting his critique of the American health care and economic system. In news conferences and during a live stream, Mr. Sanders has opted to make the case against American capitalism instead of attacking Mr. Biden.

Mr. Biden, meanwhile, has pivoted to attacking Mr. Trump and his administration’s stewardship of the coronavirus pandemic. He’s inviting Sanders supporters into his coalition, no longer attacking his ambitious ideas as unworkable or painting Mr. Sanders as someone guaranteed to lose a general election.

That leaves the two candidates onstage each eyeing opponents other than the man standing to his side. For Mr. Biden, it’s the president. For Mr. Sanders, it’s the whole system.

This may be the last Democratic debate of 2020.

The coronavirus pandemic has brought American political life to a halt. Mr. Biden and Mr. Sanders won’t be hitting the campaign trail for a while. Primaries next week in Georgia and in early April in Louisiana are postponed.

The Democratic National Committee’s debate plan allowed for one more debate in April, if it turned out to be necessary. But given the wholesale shutdown of the political season and the party’s shift toward Mr. Biden since he won the South Carolina primary Feb. 29, it’s now far more likely the nomination will be settled in a month than still being contested.

As it is, Sunday’s debate is a bare-bones operation. It’s taking place in a CNN studio with a skeleton staff, as the cable network and the campaigns have told all but a handful of employees to stay home. The D.N.C. hasn’t arranged a television partner or a host city yet for an April debate — and making arrangements for one is hardly at the front of anyone’s mind at the moment.