For those practicing their social distancing, tonight’s eleventh debate in the Democratic presidential primary cycle will provide an example of sorts. For one thing, the DNC made sure not to have a younger woman expose the two elderly frontrunners unnecessarily to any viruses. Sorry, Tulsi Gabbard, but you’re doing it for America!

Actually, it’s rather amazing that this debate will take place at all. It’s almost assuredly too late for it to have any real impact on the nomination now, especially with some states now postponing their primaries due to coronavirus concerns. Joe Biden has a 154-delegate lead at the moment and is getting closer to halfway to the magic number of 1,991 — the number of delegates needed for a first-ballot win at the convention. Bernie Sanders would need to win somewhere north of 55% of all the rest of the primaries to catch up in the proportional-allocation system. It’s not even certain Bernie can hit 55% in any one state, let alone all the rest of them.

Still, Sanders is not yet going quietly into retirement. As I wrote earlier at The Week, Sanders has one shot at taking down Biden, and that’s tonight. But Biden has something to prove, too — that he’s not just falling into the nomination by default:

The Biden tsunami of the past week has been stunning. Before Biden won in South Carolina — his first-ever presidential primary win — the question appeared to be whether the Democratic establishment could prevent Sanders from using a split field to gain enough delegates to win on a first ballot. Sanders had either won or virtually tied in the first three contests of the season (Iowa, New Hampshire, and Nevada) while Biden had finished largely out of contention in all three.

This raises a key question, both for Sunday’s debate and for the general election. Did Biden stage an impressive and historic comeback to prove his electoral mettle? Did Sanders suffer a historic collapse instead? Or did everyone misread the 2016 electoral cycle as a populist uprising, when in fact it might have been a rejection of one specific person across the partisan divide: Hillary Clinton?  …

After winning South Carolina and having the remaining center-lane candidates drop out, Biden began winning in places he’d barely visited — Minnesota, Massachusetts, Maine, and arguably Texas — where Sanders had been presumed to be ahead. Polls suggested that Sanders would score a huge delegate advantage over Biden in progressive California, but Biden finished within seven points of Sanders and with just 50 fewer delegates.

The impression this leaves is of a candidate who is winning by default, not by skill or argument. Exit polls favoring electability over policy amplify that impression. Sanders must believe that to be true, too, which is why he’s defying the delegate math for a few more days to take a direct run at Biden on stage. All Biden has to do at Sunday’s debate is survive it without doing too much damage to his own case. Sanders can only win now if Biden stumbles so badly as to make himself the more dangerous choice in a general election, and it will take a historic stumble to make the Fidel apologist the safe choice.

Speaking of safe, how strange is it that the DNC is allowing this to go on at all? This debate got moved from Arizona and a live audience to Washington DC and a CNN studio because of the coronavirus outbreak, but it would have been almost as easy to just cancel it over that issue. Giving Sanders a free shot in a one-on-one forum at the obvious nominee is a major risk, especially given questions about Biden’s overall stamina. For all his other faults and health issues, Bernie’s energy has been constant in these debates, while Biden has a tendency to fade as they go on. When there are several candidates on stage at once, that isn’t as noticeable, but if Biden starts slowing down, he’s got nowhere to hide.

Strange, then, that the DNC didn’t invite Tulsi Gabbard to join the debate. Gabbard has won two delegates and has refused to exit the race, and she has defended Biden in previous debates against attacks from the left. One has to wonder if this isn’t a sop to Sanders and the Bernie Bros — to give him one last unfettered shot to make his case and then to withdraw after Tuesday’s round of primaries. That’s a risk, but it’s also a test of Biden’s stamina to see if he can keep up against Sanders — and prove he can maintain his stamina against Donald Trump.

The debate will air on CNN tonight at 8 pm ET, with Dana Bash, Jake Tapper, and Univision’s Ilia Calderón moderating. We may or may not be updating this post during the debate, but we’ll likely be commenting on Twitter, so you can follow along below with the Townhall crew.