Politico published a new poll in cooperation with the Morning Consult Center that showed only 44% of respondents approve of US President Joe Biden's job performance, while only 46% think he is "mentally fit".

Politico reported that voters are growing increasingly skeptical about the health and mental fitness of Biden, the oldest president ever sworn into the White House, according to the new poll.

Only 40% of voters surveyed agreed that Biden was "in good health", while 50% disagreed. 

The 10% point gap - outside the poll's margin of error - represents a massive shift from 29 points since October, when Morning Consult last conducted a poll for the same question and found that voters believe Biden is healthy by 19 points in his favor.

When asked if Biden is mentally fit, voters were roughly evenly divided, with 46% saying he is and 48% disagreeing. But this negative two-point margin stands in stark contrast to Biden's numbers last October when voters thought he was mentally fit with 21 points in his favor.

Politico said the poll questions are part of a long line of traits based on which voters have been asked to rate Biden — the same set of questions was used multiple times during Donald Trump's presidency, and they were asked about both candidates last fall, ahead of the 2020 presidential election.

The new poll comes in light of persistent questions about whether Biden - who turns 79 on Saturday - will run for re-election within three years, and with Democrats increasingly concerned about the Party's aging. 

Biden says he will run again, but some of his old allies have raised doubts. Even Saturday Night Live lashed out at Biden about whether he was "lucid".

Previously, extensive assessments of Biden's age and verbal errors were limited to conservative news outlets and social media, said Selinda Lake, a Democratic pollster who polled for Biden.

“They’re running a very aggressive campaign on this, and it’s bleeding over into the mainstream a little,” Lake said. “By and large, the people who believe this are Trump supporters anyway or they’ve been exposed to the right-wing disinformation machine.”

Lake believes that the Morning Consult poll generally shows that Trump voters and Republicans think Biden is neither physically nor mentally fit, and Biden voters think the opposite. However, independents - by a margin of 23 points - disagree that Biden is now mentally sound.

Before last year's election, independents and voters, in general, believed Biden was more physically and mentally fit than Trump, whose mismanagement of the coronavirus pandemic hit his campaign badly at a time Biden's camp embraced social distancing and mostly avoided big events.

But now that Trump is away, Biden is more in the spotlight than ever, and his overall popularity ratings began to collapse with the chaotic withdrawal from Afghanistan. 

The ravages of the delta outbreak, disputes in Congress, and public perceptions about the economy have all contributed to Biden's growing problems.

The new Morning Consult poll showed that 44% give Biden a positive rating to approve his position and 53% oppose. 

Biden's approval rating has not changed over the past two weeks - it was 46% last week and 45% the week before - since the infrastructure bill was passed in Congress earlier this month.

A recent Harvard and Harris Center poll showed that 53% of voters said they had doubts about Biden's health, while 47% did not. When asked if Biden is too old to be president, 58% said he is, while 42% said he is still fit. 

“Biden is definitely slow on a lot of things. I’m not sure if it is because of his age, or if he’s still going after 30 decades ago,” one respondent joked, according to a transcript. On whether she would support Biden in 2024, the woman said, “If he’s alive. I’m just saying.”