The results show the extent to which voters’ views on the coronavirus crisis and Mr. Trump’s management of it continue to hang over the election.

Voters in Nevada said, by a 10-point margin, that they trusted Mr. Biden more than the president to handle the pandemic. In Ohio, Mr. Biden’s advantage on the question was seven points.

About one-third of voters in each state said Mr. Trump did take adequate precautions to protect himself, while 62 percent in Nevada and 58 percent in Ohio said he did not.

And asked how politicians should campaign during the pandemic, just 20 percent of Ohio voters and 28 percent of Nevadans said it is appropriate to appear in person before large crowds. Sixty-five percent of Ohioans and 58 percent of Nevada voters said candidates should campaign only in front of small, socially-distanced groups.