Joe Biden holds his own with a little help from some debate rivals. That aid could be the real news here.

Joe Biden held his own Thursday night on the stage of Texas Southern University, which means the two-hour-and-45-minute debate presented by ABC probably won’t result in any major change in the standings among the top Democratic candidates.

But something more subtle happened in tandem with Biden’s performance that could make a big difference in the former vice president ultimately locking down the party’s nomination. Some ground shifted under the feet of the 10 candidates on that stage, and it was mostly to Biden’s advantage.

The trigger moment came with Julián Castro going after the former vice president for statements the 76-year-old Biden made in answer to questions about his vision for health care. At issue was whether certain persons would automatically be enrolled in his plan or would have to buy in. It came near the end of what had been a wide-ranging, informative and spirited conversation about health care among all the candidates. But the tone became decidedly less civil with Castro’s attack on Biden.

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Castro claimed Biden had said persons would have to buy in and then two minutes later said they would be automatically enrolled.

Biden forcefully denied that.

“Are you forgetting what you said two minutes ago?” Castro asked sarcastically. “Are you forgetting already what you said just two minutes ago? I mean, I can’t believe that you said two minutes ago that they had to buy in and now you’re saying they don’t have to buy in. You’re forgetting that.”

The not-so-subtle subtext here was about Biden’s age and lapses he had been having when it comes to details and facts in recent weeks.

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“I’m fulfilling the legacy of Barack Obama, and you’re not," Castro said, ticking his aggression up another notch.

“That’ll be a surprise to him,” Biden replied standing his ground.

But that’s when others stepped in to shut down Castro’s attack.

“Come on, guys,” Andrew Yang said.

“This is why presidential debates are becoming unwatchable,” Pete Buttigieg added.

“Yeah,” Amy Klobuchar chimed in.

“This reminds everybody of what they cannot stand about Washington, scoring points against each other, poking at each other, and telling each other that — my plan, your plan,” Buttigieg said. “Look, we all have different visions for what is better ...”

“Yeah, that’s called the Democratic primary election, Pete,” Castro said, understanding that Yang, Klobuchar and Buttigieg were all talking to him. “That’s called an election.”

“Yes, but a house — a house divided cannot stand,” Klobuchar replied. “And that is not how we’re going to win this.”

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And that was it: The rest of the night no one came after Biden the way Kamala Harris had in an earlier debate calling him out over his stand on school busing in the 1970s. It was as if the candidates and party leaders agreed that trying to shred their front runner was no way to win the White House, and that they could have a spirited debate and, indeed, campaign without the circular firing squad Obama had mentioned several months ago in connection with attacks on Biden and the Obama-Biden record. But Castro appeared not to have received that memo.

Overall, no one had a better night than Beto O’Rourke, who seems to have found a voice that resonates with voters in the wake of a recent mass shooting in his hometown of El Paso.

From his full-throated denunciation of President Trump, saying the El Paso shooter was “inspired by our president,” to his pledge of support on reparations for slavery, he spoke with a clarity and force no other candidate could match Thursday night. Virtually every one of his opponents praised him onstage at some point for his words and actions in the wake of the shooting. He seemed the most statesmanlike of the group.

Those analysts who wrote him off will need to reconsider his candidacy. But that said, O’Rourke is still going to be in the lower tier of candidates for now.