Trump assassination attempt could force Biden to limit newly aggressive campaign

Saturday's assassination attempt on former President Donald Trump is expected to put President Joe Biden and his campaign even further on their back foot, curtailing their messaging and transforming a race in which Biden was already perceived to be faltering.

Biden will likely not be able to message as aggressively as usual, particularly on Trump's supposed threat to democracy, while democratic strategists predict that the former president will get a polling boost from the shooting and this week's Republican National Convention, where he will formally accept the GOP presidential nomination.

The fundamentally altered campaign dynamic comes amid a broader Democratic reckoning over Biden's place atop the 2024 ticket -- a debate that might only be temporarily paused.

"It makes Biden's path even more challenging since it makes it more difficult for him to highlight the risk Trump poses, especially in the short term," said one source familiar with the Biden campaign's strategy.

The shooting, which injured Trump in his right ear and led to the deaths of both the shooter and one rally attendee, is formally being investigated as an assassination attempt, heightening the tenor of an already acrimonious race.

Already, Biden's team is adjusting to the new political reality.

After the president's shaky debate performance last month, his campaign began rolling out a more aggressive campaign strategy, flying Biden out to key swing states at a rapid pace and having him sit down for unscripted interviews with the media to assure voters he's up for another four years in office.

But a campaign official told ABC News that Biden's team is "pausing all outbound communications and working to pull down our television ads as quickly as possible," and an internal memo sent by campaign leadership and obtained by ABC News asked staffers to "refrain from issuing any comments on social media or in public."

Vice President Kamala Harris also postponed her visit on Tuesday to Palm Beach County, Florida, Trump's backyard, to talk about abortion rights, according to a campaign official.

Biden in remarks Sunday urged unity after the shooting, saying he was grateful that Trump was safe.

"Unity is the most elusive goal of all, but nothing is [more] important than that, unity. We'll debate, we'll disagree, that's not going to change. But we're gonna not lose sight of the fact of who we are as Americans," Biden said from the White House.

Taken together, the assassination attempt underscores the fragile footing the Biden campaign finds itself on as it tries to prosecute a contrast with Trump while dialing down rhetoric that members of both parties said over the weekend has gotten out of hand.

"I think it forces the overall tone to be reconsidered for everyone," said one former Democratic House aide who remains familiar with dynamics on Capitol Hill, who, like others, spoke anonymously to discuss the political issue the day after the shooting.

The president's messaging accusing Trump of being a threat to democracy are expected to be particularly impacted by the shooting, sources told ABC News.

Biden had recently made the Jan. 6, 2021, insurrection and Project 2025 -- a plan that Trump has disowned that former administration officials put together for a theoretical second term -- a cornerstone of his stump speech, suggesting that the former president posed an existential risk to America's democratic foundations.

That's no longer expected to be the case.

"Message-wise, I think it means the rhetoric around Project 2025 must become even more 'Google it' with much less spin or hyper language," said one Democratic strategist.

"I think in the short term their messaging will be more focused on Biden," the source familiar with the Biden campaign's strategy added.

Other Democrats said the campaign should still try to make a case about the country's democratic foundations being at risk, though they still underscored Biden will be walking a tightrope.

"Another Trump presidency is a threat to democracy and political violence has no place in America; we can make both points simultaneously," the former House aide said.

Still, "I think the way Biden responds in the coming days will be watched closely," the person said.

Beyond arguments around democracy, the shooting could suck up so much political oxygen that it could be difficult to talk about anything besides the assassination attempt.

"It makes it harder to pivot to economic contrast for the next four years, which is the only way to win," the Democratic strategist said.

Some operatives urged caution at how much the shooting would alter the race, noting that the back-to-back events of the assassination attempt and GOP convention will take time to seep into the public consciousness.

"I can't forecast and won't make any predictions until I see new data. We realistically now have to wait for the post-assassination attempt and post-GOP convention polls to really understand where the race is. One was a seismic, unprecedented event and the other is a historical marker event in the presidential campaign," one Democratic pollster said.

Still, it's unclear if party members will follow that advice.

Democrats were already in the middle of an increasingly tense internal discussion over Biden's chances in November after his disastrous debate performance last month.

Last week, Biden sought to quell his doubters' worries with calls to key lawmakers and a press conference Thursday capping off the NATO summit.

Those efforts failed to stop more calls for his campaign's end, after some calls descended into shouting matches, and gaffes during his press conference overshadowed his comfort with complex foreign policy issues.

Now, with Trump expected to get a boost, that internal feud may only amplify, if after a brief pause.

"It freezes the public conversation about replacing Biden for the next week, but my guess is the polling post-RNC will be even worse, heightening the calls for Biden to step down at that point when members return to D.C.," the Democratic strategist said.

"I think Biden will think he's the only one who can be a healer and digs in more, which just keeps Democrats on this treadmill of having a nominee who is badly behind, but even more resistant to stepping aside."