Why does the conventional wisdom matter so much for Bush? Two reasons. First, because (as we pointed out before the debate) Bush’s “fundamentals” aren’t all that strong. He entered the debate with middling favorability ratings and polling at about 7 percent nationally. His endorsements have all but dried up: just two since Labor Day and none in the past three weeks, according to our endorsement tracker. His third-quarter fundraising totals were mediocre. This wasn’t a case like that of Hillary Clinton, who even at her worst moments was polling at 45 percent and had the overwhelming support of the Democratic establishment. Bush had a lot of work to do to gain the lead in the first place.

The other reason the conventional wisdom matters for Bush is because Bush is running a conventional campaign. It’s not as though he has all that much grassroots support: Only 3 percent of his fundraising has come from small donors. Instead, Bush needs the support of Republican elites — and favorable media coverage — to signify to reluctant Republican voters that he’s a viable nominee. And he needs their financial backing to win a potential war of attrition.