This is not the first time that the pundits have declared a Jeb Bush campaign deathwatch, but the vital signs are getting weaker and weaker, and South Carolina may provide the final blow.

The latest bad news came on Wednesday, when popular Governor Nikki Haley endorsed Senator Marco Rubio. Her backing gives Rubio another boost in his quest to consolidate the backing of the Republican establishment against Donald Trump and Ted Cruz, and it makes it even harder for Bush to do that. Bush had been angling for Haley’s endorsement too, and on Tuesday—in a moment of candor he may regret now, told NBC, “She is the probably the most meaningful endorsement if there is, if she is going to give an endorsement it would be the most powerful meaningful one in the state.”

A little bit too much honesty was Bush’s theme on Wednesday. After news of the Haley endorsement leaked, he lashed out during a trail stop. “It’s all decided, apparently. The pundits have already figured it out. We don’t have to go vote. I should stop campaigning maybe, huh? It’s all done,” he sniped, then recovered, adding: “That's not how democracy works.”

That recovery was a little late: In reaching for pugnacious underdog, Bush had instead come across as a peevish and petulant. Besides, he’s not just fighting off questions from pundits, but also from supporters.

“During the question and answer period following an unusually hot-tempered 30-minute rendition of his stump speech, Bush received unsolicited advice from three audience members in succession, each encouraging him to be tougher,” Politico’s Eli Stokols reports. “It did not improve his mood, which was noticeably tense from the get-go.”

As Saturday’s crucial South Carolina primary draws near, Bush is pulling out every remaining trick he’s got. There’s the “hot-tempered” speech, a somewhat more fiery version of his low-key, wonky presentation throughout the campaign, the one that earned him the nearly fatal “low-energy” label from Donald Trump. After months of keeping George W. Bush in mothballs, worried his still-toxic reputation would be a drag on Jeb’s chances, the campaign finally brought the former president out for an event on Monday in North Charleston. The candidate even dropped his trademark rimless glasses in favor of contact lenses, a move that he insisted wasn’t about campaign optics—so to speak—even as he admitted that he’d never worn contacts before. (Members of the Bush family have long struggled with “the vision thing.”)

How much benefit did George W.’s appearance do for his brother? As I reported at the event, it mostly served to show just how much better a politician the former president is. Voter after voter at the rally told me they admired the Bush family, and even believed that Jeb might be a pretty good president. But that didn’t mean they were supporting him. They were worried about the “dynasty” issue. They were worried about his low energy. They just thought that Marco Rubio was a better bet. The reasons varied from person to person, but the takeaway was clear: Thanks—truly, sincerely, thanks!—but no thanks.

It’s been possible for Jeb Bush to waive off some of these critiques in the past. There was no reason for him to leave before the Iowa caucuses, not with his huge war chest. And sure, after the Iowa caucus things looked bad, but then again it was never going to be his state, right? Then came New Hampshire, where he ended up in fourth place—a finish that might have spelled doom if it hadn’t come in ahead of Marco Rubio, giving Bush a slightly better argument that he could claim the establishment mantle.

That’s not really an option anymore. Polls in South Carolina show Bush still a solid distance behind a recovered Rubio (though still ahead of John Kasich, who hasn’t managed to capitalize on his strong second-place showing in New Hampshire). If he ends up fourth there, what justification will he have for continuing? He will have had poor results in the midwest, the northeast, and the south. It will show that attacks by his super PAC on Rubio haven’t vaulted their man ahead.

The influential Washington tip sheet Playbook blared Thursday morning, “GOP RACE NARROWING to 3.” It is easy, and probably correct, to insist that Playbook’s author, Mike Allen, is simply the arbiter and amplifier of Beltway conventional wisdom, but that happens to be Bush’s base. The justification for his campaign, especially at this stage, is his ability to rally and speak for Beltway Republicans. If he can’t do that, and he can’t win a primary either, why bother?