Poll: Trump trails Biden on voters' views of mental, physical fitness

More than a majority of voters say presumptive Democratic presidential nominee Joe BidenJoe BidenSenate Republicans face tough decision on replacing Ginsburg What Senate Republicans have said about election-year Supreme Court vacancies Biden says Ginsburg successor should be picked by candidate who wins on Nov. 3 MORE is mentally fit to be president, compared with less than half who said the same about President TrumpDonald John TrumpObama calls on Senate not to fill Ginsburg's vacancy until after election Planned Parenthood: 'The fate of our rights' depends on Ginsburg replacement Progressive group to spend M in ad campaign on Supreme Court vacancy MORE, according to a new Hill-HarrisX poll.

Fifty-six percent of respondents said Biden was mentally fit to lead the nation, compared to 44 percent who said he wasn't. For Trump, 45 percent said he was mentally fit to occupy the Oval Office, with 55 percent disagreeing.

The survey also found more voters said Biden, 77, was physically fit to be president compared with Trump -- 60 percent to 56, respectively.

The responses split largely along party lines.

Seventy-nine percent of Republican voters, 45 percent of independents and 17 percent of Democrats said Trump, 74, was mentally fit for office.

By contrast, 84 percent of Democrats, 52 percent of independents and 29 percent of Republicans said the same of Biden.

Voters over the age of 50 were less likely to give Trump high marks on mental fitness.

Roughly 45 percent of respondents 50 and up said Trump was mentally fit for office. Fifty-six percent of voters in the same age groups saw Biden as mentally fit.

The July 7-10 survey results come as the Trump campaign ramps up its questioning of Biden's cognitive abilities. If elected, Biden would be the oldest first-term president.

The Hill-HarrisX poll was conducted online among 2,841 registered voters and has a margin of error of plus or minus 1.9 percentage points.

Gabriela Schulte