“You know, I think Jeb Bush is toast,” I told one of my editors after Wednesday night’s debate.

“I kinda do too,” he replied. “I’m just worried because that’s what everyone else seems to think too.”

Yes, we pride ourselves on being skeptical of the conventional wisdom here at FiveThirtyEight. You don’t have to look very far back for examples of it being wrong, such as how it badly overestimated the degree of danger that Hillary Clinton’s campaign was in until a week or two ago. But being skeptical is not the same thing as being a contrarian. There are plenty of times when the conventional wisdom is right. This is probably one of those times.

Bush received poor reviews for his debate performance from political commentators of all stripes (Republican, Democratic, partisan, nonpartisan, reporters, “data journalists”), many of whom also suggested that his campaign might soon be over. The straw poll we conducted among FiveThirtyEight writers and editors agreed; Bush’s average grade was a C-, putting him at the bottom of the 10-candidate group.

CANDIDATE AVERAGE GRADE HIGH GRADE LOW GRADE Marco Rubio A- A C Ted Cruz B+ A D Chris Christie B A- D Carly Fiorina B- A- D Ben Carson C+ A- D John Kasich C B- D Mike Huckabee C B D Donald Trump C B+ D- Rand Paul C- B- F Jeb Bush C- B F

I agree with the group (I gave Bush a C-). Bush lost a probably ill-advised confrontation with Marco Rubio over Rubio’s absences from the Senate. Bush’s closing statement seemed stilted. He was the setup for a Chris Christie applause line about fantasy football. And for much of the debate, he was an afterthought, receiving the second-lowest amount of talk time among the candidates.

None of these things, taken alone or even together, would ordinarily be all that damaging. Bush didn’t make a catastrophic mistake — an “oops” moment. But the media consensus seemed to be that the debate was a potential make-or-break moment for Bush. Even if you were to charitably round up Bush’s performance to a C+ or B-, it probably wasn’t good enough.

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.

Instead, before the debate, major Bush donors were fretting openly to reporters (not just swiping at Bush anonymously) that his campaign was in a potential “death spiral.” Those concerns may grow larger and louder now, especially given that Rubio and (in my view at least) Christie had effective debates and are plausible replacements for Bush in the “establishment” lane of the GOP field.

Could Bush ride out the storm? Maybe. But his problem isn’t a mere lack of “momentum”; his candidacy has always been flawed. Instead of being the most electable conservative — the traditional profile of the Republican nominee — Bush has never looked all that electable or all that conservative.

And Republicans have a lot of alternatives. While Rubio has some problems too — his third-quarter fundraising was pretty abysmal, for instance — he fits the profile of the electable conservative. If Rubio were to falter, the Republican establishment would have a few backup options left, such as Christie or John Kasich (or in an emergency, even Mitt Romney). These candidates also have flaws, Christie especially, but they aren’t necessarily more severe than Bush’s.

In the insurgent lane, Ted Cruz, a candidate whose chances were already on the upswing, probably helped himself during the debate. It’s possible that Cruz’s gains will come at Donald Trump’s expense, although I personally thought Trump did fine and that if Cruz gains in the polls, it could come from Ben Carson or some other candidate instead.

But whether it’s Cruz or Trump or Carson ahead, the Republican establishment can’t wait that much longer to get its act together. And the most expedient way to do that may be to kick Bush to the curb.

Check out our live blog of Wednesday night’s Republican debate.