Voters say they were aware of former President Joe Bidens decline, and believe the administration lacked honesty and transparency about his mental fitness, with many wanting Congress to investigate the matter.A new Fox News survey finds more than half, 52%, think it is important to investigate whether Biden advisors used an autopen without the presidents awareness, while 46% say its time to move on.House Oversight Committee Chair James Comer is pursuing investigations against former Biden administration staff for allegedly covering up Bidens mental decline and using an autopen for executive actions.Views are split on whether advisors should be scrutinized for making key presidential decisions on behalf of Biden (50% investigate vs. 49% move on), while a majority opposes investigating whether Biden advisors covered up his decline (44% investigate vs. 55% move on).FOX NEWS POLL: VOTERS THINK IRAN POSES A REAL THREAT TO US SECURITY, BUT SPLIT OJ ISRAEL'S STRIKEAmong Democrats, one in five supports investigating whether there was a cover-up, while roughly one in four feels that way about using the autopen and making presidential decisions.Overall, 68% of voters believe the previous administration was dishonest about Bidens condition, including 52% of Democrats, 75% of Independents, and 81% of Republicans.FOX NEWS POLL: ECONOMIC PESSIMISM ABATES SLIGHTLY AS VOTERS REFLECT ON THE ECONOMYYet, while a majority agree there was a cover-up, they werent fooled.Nearly 7 in 10 say they were aware of Bidens cognitive condition even before his jaw-droppingly bad debate performance in June 2024. Some 28% say they knew he was in decline as soon as he took office, 21% say a couple of years into his term, and 19% after he started running for re-election.Another 20% knew of Bidens decline after his debate with Donald Trump. Fewer than 1 in 10 say he wasnt in decline (9%).These numbers are consistent with what voters said throughout Bidens term.As early as November 2021, only one year after Biden was elected, Fox News surveys found that a 53% majority thought his age was interfering with his job as president, including more than one-quarter of Democrats. By the 2022 midterms, our Fox News Voter Analysis election survey found 57% of voters felt Biden lacked the mental capability to serve and, by July 2024, that grew to 65%."Somewhat lost in the kerfuffle about the exact timing of Bidens decline is the fact that most knew he was losing it and had factored this into their vote choice long before the presidential debate," says Daron Shaw, a Republican who conducts the Fox News survey along with Democrat Chris Anderson. "Still, Bidens reputation and legacy are clearly taking a hit as the real history of his administration is revealed."Bidens current personal favorability is underwater by 13 points (43% favorable, 56% unfavorable), compared to -19 points in January. During the early days of his presidency, his ratings were net positive by 10 points (54% favorable, 44% unfavorable, April 2021).Today, 75% of Democrats have a positive view of Biden, down from 95% four years ago.CLICK HERE FOR CROSSTABS AND TOPLINEConducted June 13-16, 2025, under the direction of Beacon Research (D) and Shaw & Company Research (R), this Fox News survey includes interviews with a sample of 1,003 registered voters randomly selected from a national voter file. Respondents spoke with live interviewers on landlines (149) and cellphones (566) or completed the survey online after receiving a text (288). Results based on the full sample have a margin of sampling error of 3 percentage points. Sampling error for results among subgroups is higher. In addition to sampling error, question wording and order can influence results. Weights are generally applied to age, race, education, and area variables to ensure the demographics are representative of the registered voter population. Sources for developing weight targets include the American Community Survey, Fox News Voter Analysis, and voter file data.Fox News Victoria Balara contributed to this report.