This is the same poll I posted last week that showed Carson suddenly bouncing out to a seven-point lead. On the one hand, it’s an online poll; on the other hand, it’s a poll of likely Republican voters, not just registereds. (And a big sample too.) For whatever reason, Carson started to climb in Reuters’s five-day tracker on October 22nd and kept climbing, peaking at 33 percent on October 28th — the day of the third debate.

Six days later, the lead is all gone. Trump 32, Carson 20.2, Rubio 11.6.

The red line tracks Trump’s numbers while the purple line tracks Carson’s. It’s weird to see him drop so suddenly when the big news today in national polling is a surprising lead for him over Trump in the WSJ/NBC survey, but the two results aren’t necessarily inconsistent. Remember, that WSJ/NBC poll was conducted from October 25th to the 29th, the same period when Carson was peaking in Reuters’s numbers. What you might be seeing in the graph above is Carson’s support suddenly bucking because of a poor debate performance. The WSJ/NBC wouldn’t have captured that because the poll ended too soon. We could be seeing the very beginning of a Carson fade here that’ll only become fully clear in other polls later this week.

Or we might not. Carson’s actually gotten mostly good reviews for his last debate performance — nothing spectacular but nothing damaging either. When YouGov asked Republican voters if their opinions of different candidates got better or worse after the debate, 35 percent said their opinion of Carson improved versus just four percent who said it got worse. The numbers for Trump were 30/11. There’s no reason to think that Carson somehow blew himself up at the debate. What you’re probably seeing in the Reuters data has less to do with him collapsing then merely returning to the level he was at for several weeks before his mysterious surge in late October. He and Trump now have almost identical numbers to the numbers they had on October 22nd.

Exit question: Rubio, represented by the green line, is up to 11.6 percent in today’s poll, higher than he’s been for most of the past three weeks, which suggests a small debate bounce. Interestingly, though, Jeb Bush is also a bit higher than where he was in mid-October. How do you explain that given the universal consensus that the debate was a very bad night for him at best?