All eyes were on Bernie Sanders, but this debate was also Joe Biden’s last stand. He’s hanging on to a narrow lead in South Carolina, and the stakes are about as big as they could be.

Consider: If Biden loses South Carolina to Sanders, he’s just about done. If he wins, however, all kinds of interesting things potentially start happening. Pressure will mount on the other moderates to get out and rally behind him to make this a Sanders-Biden race (combined age: 155)—at least, pending how Bloomberg does on Super Tuesday, on which he’s placed his big bet, meaning perhaps it’ll be a Sanders-Biden-Bloomberg race for a bit (combined age: 233, or about 10 years younger than America).

So how’d Joe do, man?

He started out strong, I thought. Not “strong for Joe Biden,” but actually strong. His hit on Sanders on the Brady bill was effective (and was obviously playing to a sympathetic house). He quickly mentioned that Sanders wanted someone to primary Barack Obama in 2012. Could have done that one more effectively, but at least he got it in there.

As the night dragged on, though, things went downhill. There was another of those trademarked weird Biden moments, when he said 150 million people had been killed from gun violence since 2007, which was only off by a factor of about 149.7. He did too much complaining about the rules: “Why am I stopping? No one else stops!” He started out saying he was just going to barge through the time limits, then he shifted to cutting himself off in ways that were very strange, but he did manage to bail himself out the last time he cut himself off with an Actual Apparently Improvised Line (“must be my Catholic school training”).

But he couldn’t deliver any knockout punches on Sanders. None of them really did. They kept him playing defense, so he had a less good night than usual. But I don’t understand why these people can’t just throw a punch.

“ This is the big leagues. These people are running for president. They’re supposed to be good at this. Why are they bad at it? ”

The key exchange between the two came on the Cuba question. Sanders said: “I said what Barack Obama said in terms of Cuba, that Cuba made progress on education.” That’s true, but it was in a totally different context. Obama spoke those words as president while opening up diplomatic relations. He did not have a history of praising Cuba and the USSR and Sandinista Nicaragua. They aren’t remotely the same thing.

The audience, presumably very pro-Obama, was at that moment booing Sanders. They were primed for a takedown. Biden’s response: “[Obama] did not in any way suggest that there was anything positive about the Cuban government. He acknowledged they did increase life expectancy but he went on and condemned the dictatorship, he went on and condemned the people who, in fact, had run the committee. He also made sure to make it clear—and by the way, I called to make sure that I was prepared—I never say anything about my private conversations with him, but the fact of the matter is he, in fact, does not, did not, has never embraced an authoritarian regime and does not now.”

What? He didn’t say “anything positive” about Cuba, but then in the next sentence he praised the increase in life expectancy. And, uh, what committee? And, uh, what’s that about a private conversation? What did you say, Joe? What?

How about something like this: “Bernie, President Obama spoke those words when he was opening diplomatic relations—a truly historic move that took years of diplomatic groundwork and preparation. He didn’t just go around praising Castro willy-nilly. And he sure didn’t say in the 1980s, as you did, that he sympathized with Fidel Castro against Jack Kennedy, and that President Kennedy, Democratic President John Fitzgerald Kennedy, almost made you puke.”

Boom.

I mean, really. This is the big leagues. These people are running for president. They’re supposed to be good at this. Why are they bad at it?

The smartest thing Biden said all night was probably the very last thing: that he’ll make sure to put a black woman on the Supreme Court. Huge applause for that one. That’s the kind of easy, quick, memorable thing that people will discuss for the rest of the week over the water cooler.

So Wednesday, Biden will get Jim Clyburn’s endorsement. Twenty years ago, that would have put a lid on things. But stuff doesn’t quite work like that anymore, as we know. We’ll have to see who comes out to vote. Maybe four days of barnstorming the state with Clyburn and other prominent black leaders will get Biden over the finish line.

And if he wins, the race enters a new phase. The conversation will move immediately to when will the others drop out. If the establishment people want to stop Sanders, Biden is probably still the best bet, but he’s a pretty rickety contraption for them all to be riding.