Many Democrats are apathetic about Biden in 2024 but say it's not a dealbreaker

President Joe Biden touted his achievements during his second State of the Union address on Tuesday and seems to be gearing up for an expected 2024 presidential run -- but polling shows many Democratic voters aren't thrilled about this.

Nearly six in 10 Democratic-aligned adults don't want to see Biden renominated, a new ABC News/Washington Post poll found.

ABC News spoke with some of those who participated in the survey to learn more about their views on Biden and their concerns about a 2024 campaign.

Many of them had issues with his age but said that, despite their apathy, they would still cast a ballot for him against a Republican like former President Donald Trump or Florida Gov. Ron DeSantis.

Biden, who is currently the oldest sitting president at 80, would be 82 if he is inaugurated for a second term and would be 86 when he left the White House.

Democrats like Stephen Couture, 68, think someone younger should be the party's nominee in 2024.

"He's done a fine job. That's not the issue," Couture said. "Where's his mental state gonna be another six years from now if he would be president again?"

Biden has repeatedly pushed back on the suggestion that he is now or will be too infirm to carry out the office.

"I think it's a legitimate question to ask anybody over 70 years old, whether or not they're fit and whether they're ready. But I just, only thing I can say to the American people, it's a legitimate question to ask anybody: Watch me," Biden told ABC News' David Muir in an interview in 2020, before he was elected to his first term.

He said much the same in October, in an interview on MSNBC: "I think the best way to make the judgement is to watch me. Am I slowing up? Am I going at the same pace?"

Speaking with ABC News, Couture said he feels the economy is doing well under the Biden administration, especially because a recession has so far been avoided and despite relentless Republican criticism of high inflation.

"Despite so many Americans, other polls, saying that he's not doing well with the economy, from my perspective, the economy's doing pretty well," he said, referring to a slew of surveys showing Biden's handling of the economy is not approved of by most Americans.

Biden acknowledged inflation wasn't falling "fast enough" for Americans but nonetheless boasted of the country's economic success during his second State of the Union address. Couture said he watched the speech, though it didn't change his mind about a younger candidate.

Couture has voted for a variety of candidates from different parties in past presidential elections, he said, and looks at "the issues and the person running, and [I] vote for the person more than the party."

In the 2024 presidential election, Couture said that if Biden was the nominee, his choice would depend on who the third-party candidate is -- but that if it was Biden running against Trump, who announced his own 2024 campaign in the fall, he would stick with Biden.

Couture, who is from South Bend, Indiana, said he would like to see U.S. Secretary of Transportation Pete Buttigieg as the Democratic nominee. Buttigieg was previously the mayor of South Bend.

In a recent interview with ABC News' Jonathan Karl on "This Week," Buttigieg said "he [Biden] is an absolutely historically successful president, and I want to see that continue."

Other Democrats like 54-year-old Stephanie Whitney of Virginia feel that Biden has "done an extraordinary job," but that it's time for "some new voices."

"I think that the Democratic Party has not done a great job of allowing younger leaders to take a more prominent role," Whitney said. "I do think that they're getting better in terms of [House leader Hakeem] Jeffries and other representatives, but I think it's still limited."

Hurshel Burt, 62, said he likes Biden's policies but also shares worries over his age.

"He looked pretty good the other night in the State of the Union," said Burt, who is from Alabama. "But it would be nice to have some younger blood in."

Vice President Kamala Harris asked about the poll on ABC's "Good Morning America" Wednesday, said of Biden, "I think that age is more than a chronological fact, to be very frank with you."

"I think what people want to know is what have you done and when you look at what President Biden has achieved, what our administration has achieved, not to mention foreign policy, something you care deeply about and have worked on, I think you will see that we have a very bold and vibrant president in Joe Biden," Harris said.

Burt's main concern regarding the president's age is his physical capability to serve as he gets older. He said he is also a fan of Buttigieg as a possible candidate, "but he's so young, I don't know if he can get elected."

Like many Democrats who spoke with ABC News and who do not favor Biden as a nominee, Burt said he would still vote for the president in 2024 rather than Trump or DeSantis.

Charles Ewell, a 65-year-old from Virginia, thinks like Burt, Couture and Whitney that Biden is "just a little too old."

Ewell said he would support a candidate like Gavin Newsom, the governor of California, or Buttigieg. (Newsom said last year, before he was reelected, that he would serve his second full term as governor.)

But Ewell said that if it came down to Trump and Biden again, he would vote with the Democratic Party.

Other voters like Joseph Bartek, 79, of Pennsylvania think a woman should hold the position.

Bartek said he has voted Democratic since the George W. Bush administration and also feels someone younger should get a shot at the presidency.

David Ramunno, 59, of Michigan, thinks that the position "demands more than what someone of that age is going to be able to do."

His primary concern is over Biden's mental capability to serve, he said.

But Ramunno does support many of the Biden administration's policies, including seeking to reduce federal student loan debt.

"I don't really have any issue with any of his policies," Ramunno said. "It's just age."

"If it comes down to it, and he's the Democrat, I'll probably still vote for him," Ramunno said.