Democrats Express Deep Anxiety as Polls Show Biden Trailing Trump

White House officials on Sunday shrugged off weekend polling that showed President Biden trailing former President Donald J. Trump, even as Democrats said they were increasingly worried about Mr. Biden’s chances in 2024.

The new polling from The New York Times and Siena College found Mr. Biden losing in one-on-one matchups with former President Donald J. Trump in five critical swing states: Arizona, Georgia, Michigan, Nevada and Pennsylvania. Mr. Biden is ahead by two percentage points in Wisconsin.

Although the polling is worrisome for the president, Mr. Biden still has a year to campaign, which his team emphasized on Sunday. They noted that polls have historically failed to predict the results of elections when taken a year ahead of time.

“Gallup predicted an eight-point loss for President Obama only for him to win handily a year later,” said Kevin Munoz, a spokesman for Mr. Biden’s campaign. “We’ll win in 2024 by putting our heads down and doing the work, not by fretting about a poll.”

Still, the results of the poll, and other recent surveys showing similar results, are prompting public declarations of doubts by Democrats.

David Axelrod, a Democratic strategist who has expressed concerns about Mr. Biden before, wrote on X, formerly known as Twitter, that the new polling “will send tremors of doubt” through the party.

“Only @JoeBiden can make this decision,” Axelrod wrote, referring to whether the president would drop out of the race. “If he continues to run, he will be the nominee of the Democratic Party. What he needs to decide is whether that is wise; whether it’s in HIS best interest or the country’s?”

In a follow-up interview, Mr. Axelrod said he believed Mr. Biden, 80, had achieved a lot during the past three years but was rapidly losing support largely because of concern about how his age affects his performance.

“Give me his record and chop 10 to 15 years off, I’d be really confident,” Mr. Axelrod said. “People judge him on his public performance. That’s what people see. That’s where the erosion has been. It lends itself to Republican messaging.”

Senator Richard Blumenthal, a Connecticut Democrat, said on CNN’s “State of the Union” program on Sunday that he was concerned “before these polls.”

“And I’m concerned now,” he said.

“These presidential races over the last couple of terms have been very tight,” he said. “No one is going to have a runaway election here. It’s going to take a lot of hard work, concentration, resources.”

Donna Brazile, a former chair of the Democratic National Committee and a supporter of Mr. Biden, said, “don’t count out Joe Biden” on ABC’s “This Week” program. But she added that Democrats should be mindful of the polling from The Times.

“I would say a wake-up call once again for Democrats to be reminded that they have to go back out there, pull the coalition that they allowed Joe Biden to break new ground in 2020, especially in Arizona and Georgia, but more importantly to bring back that coalition,” she said. “Without that coalition, it’s going to be a very, very difficult race.”

Mr. Munoz declined to comment on the specifics of the Times/Siena poll.

Julie Chávez Rodríguez, Mr. Biden’s campaign manager, said in a memo released on Friday — before the Times poll was public — that it would be “crucial” for Mr. Biden to show strength among key parts of his coalition in order to win.

The weekend poll results, including a 10-point deficit behind Mr. Trump in Nevada, strike at the heart of the argument the president’s campaign advisers have been making for a year: that voters will back Mr. Biden once they are presented with a clear choice between him and his predecessor.

In her memo, Ms. Rodríguez said “voters will choose between the extremism, divisiveness and incompetence that extreme MAGA Republicans are demonstrating — and President Biden’s historic record of accomplishment.

“The American people are on our side when it comes to that choice,” she wrote.

The Times polls presented voters with that choice, and many of them, including Democrats, said they would pick Mr. Trump if the election were held today.

Already, there were signs that the campaign is scrambling to address the vulnerabilities on display in the poll among young, Black and Hispanic voters.

Last month, the campaign quietly started two pilot programs aimed at bolstering support among Democrats in two key states, Arizona and Wisconsin. In each state, the campaign has hired 12 full-time staff members to test their assumptions about how Mr. Biden is viewed by particular groups and what he needs to do to earn their votes.

In Arizona, the new staff members in two offices in Maricopa County will focus on Latino and female voters in that state. In Wisconsin, staff members will work out of an office in Milwaukee to evaluate the president’s message for Black and young voters in the state.

Campaign officials say the idea is to use the next several months to test new ways of communicating to those voters. Those include the use of “microinfluencers” who are popular on social media platforms, and “relational” campaigning, in which the campaign reaches out to voters through their network of friends rather than impersonal ads.

One of the central arguments of the Biden campaign is a belief that polls taken now, by definition, do not take into account the robust campaign that will unfold during the course of the next year.

Mr. Biden has already generated a significant campaign war chest. The president and Vice President Kamala Harris have $91 million in cash on hand and are expected to raise hundreds of millions more for use during the general election campaign that will begin in earnest next summer.

The president’s campaign aides say they are confident the polls will shift in Mr. Biden’s direction once that money is put to use attacking Mr. Trump (or another Republican, if Mr. Trump loses the nomination) and reaching out to voters.

That is similar to the argument that Mr. Axelrod made in September 2011, when Mr. Obama was trailing badly in the polls.

“The president remains ahead or in a dead heat with the Republican candidates in the battleground states that will decide the election in 2012,” Mr. Axelrod said at the time. “And ultimately it is in those battleground states where voters will choose, 14 months from now, between two candidates, their records, and their visions for the country.”

But Mr. Axelrod said he believed Mr. Biden is further behind now than his candidate was in 2011.

He said he believed Mr. Biden would continue to run for re-election, and would likely end up facing Mr. Trump again next year. He urged Mr. Biden and those around him to begin attacking Mr. Trump politically to make it clearer what a Trump victory in 2024 would mean for the country.

That kind of “competitive frame” is more important now, Mr. Axelrod said, than trying to tell people about the accomplishments that Mr. Biden has made.

“I think he’ll run,” Mr. Axelrod said. “I think he will be the nominee. If so, they need to throw the entire campaign into a very, very tough competitive frame very quickly.”