Joe Biden has a plan to bounce back. Many Democrats aren't buying it: ANALYSIS

"He's toxic. It's over," said one Democratic source.

After President Joe Biden's disastrous debate last month, a consensus arose: the path back from the electoral brink would be laid down with a blitz, including campaign travel, unscripted appearances and an overall more muscular tone.

Biden's campaign appeared to agree. It sent him to Pennsylvania and Wisconsin; sat him down with ABC News' George Stephanopoulos, following up with an interview with NBC News' Lester Holt this coming Monday; Biden himself sent a forceful letter to congressional Democrats that he would not end his campaign; and on Thursday, top aides were being deployed to calm senators and Biden will hold his first solo press conference in months.

That doesn't seem to have worked.

Democrats continued to agonize this week over his electoral chances, with additional House members, Sen. Peter Welch, and fundraising powerhouse George Clooney adding to the calls for the end of his reelection bid. Even those who didn't outright call for his campaign's end -- such as former Speaker Nancy Pelosi, who said the decision on whether to continue was Biden's alone -- seemingly brushing past the fact that he said he had made up his mind to stay in the race.

This week raised the question of what -- if anything -- could ease Democrats' dread of a possible comeback by former President Donald Trump.

"None of that matters," one informal adviser to Biden's campaign said of the president's recent activities. "He's toxic. It's over."

"The president's advisers are trying to buy time thinking this will go away," the person added about the campaign's emphasis on Biden's performance at this week's NATO summit. "It's not going away."

Pressure was high on Biden, with congressional Democrats' return from a well-timed recess and NATO's 75th anniversary summit in Washington putting a spotlight the size of the world on whether he could continue as his party's 2024 nominee.

The president started the week by sending House members his letter insisting he's staying in the race, an opening salvo that initially appeared to intimidate some lawmakers and prevent the floodgates from opening on Tuesday, even amid more widespread handwringing. He also delivered a strong -- and scripted -- speech Tuesday opening NATO's summit.

That's pretty much where the good news ended.

Biden was hit with a one-two punch Wednesday when Clooney released an op-ed saying that Biden appeared at a recent fundraiser the same way he did at last month's debate, when his disjointed answers and empty gaze sent Democrats into a frenzy. Pelosi also appeared on MSNBC's "Morning Joe" -- a Biden favorite -- to call on the president to make up his mind about running, appearing to reopen a discussion the president made a point of trying to close.

Pelosi's talking point spread like wildfire in Washington, with Democrat after Democrat appearing to try to call Biden's bluff and deny that his decision that he wouldn't drop out was final. Welch capped off Wednesday by becoming the first senator to call for Biden to drop out.

To be certain, Biden also racked up wins -- members of the influential Congressional Black Caucus rallied to his side, and no current member of congressional leadership has fully abandoned him.

Looming over it all, though, was the debate.

More than 50 million Americans watched last month's disastrous debate, a figure that marked a drop in ratings for such an event, but that will be hard for any of his appearances to match.

"That does not convey the mental capacity that they want to see in the commander in chief," one source familiar with the Biden campaign's strategy told ABC News of the president's speeches and his upcoming press conference. "The real test of that was the debate, and he failed."

Underscoring how sustained the worries are weeks later, an ABC News/Washington Post/Ipsos poll released Thursday showed that a whopping 85% of adults believe Biden is too old for a second term, though the horse race with Trump remains statistically tied. Fifty-four percent of self-identified Biden supporters said the president should end his campaign.

"I think once the wound is open, it's going to take longer than a week to heal," said James Zogby, a veteran Democratic National Committee member and pollster.

"Nobody's paying attention to whether he sinks the three pointer. They're going to say, 'is he limping?' It's like a basketball player back from an injury," he added. "That's not a good place to be when you want to have the focus be on your vision for the future and the comparison with your competitor."

Not all Democrats are as pessimistic.

Strategist Simon Rosenberg said Biden's campaign cannot ignore voters' concerns over the president's age and that the party will have to "fight like hell," but that the more aggressive playbook will help.

"There aren't that many tools in the toolbox, but certainly, I think the president's going to have to be more accessible in unscripted moments in the coming weeks so that people can see him responding to voters, responding to reporters, to have a greater certainty that that was just a bad night and not something that was more representative of his current state," he said.

"I think it's an important step," he added of Biden's week.

Democratic lawmakers, though, appear to have been rubbed the wrong way by how Biden's strategy is playing out so far.

In the course of Biden's interview with Stephanopoulos, the president said he could live with a loss if he tried his hardest in the race -- a comment that sparked ire on Capitol Hill.

"I think that was an incredibly arrogant comment that misses the point. When you run for office, one of the things you have to guard against is thinking that it's all about you," Democratic Rep. Adam Smith said. "I think this has become too much about Joe Biden, his ego, whether or not people respect him … So, I don't think that answer gave the situation the depth and the seriousness that it deserves."

And it remains to be seen if any campaign strategy, no matter how aggressive, can stack up to an anticipated deluge of Republican spending highlighting the president's biggest missteps from his tete-a-tete with Trump.

Already, Republicans are going on offense, with the House and Senate GOP campaign arms going up with such ads targeting down-ballot Democrats, threatening a Republican takeover of Washington in November.

"It doesn't matter. You're gonna have $1 billion playing that on every screen, digitally, on TV, radio, however you want to look at it, everybody's gonna be seeing it over and over with one tagline: what happens behind closed doors?" the informal campaign adviser said. "I'm sorry, we got to take Uncle Joe's car keys away."