The chart above is from the USA Today / Suffolk University Poll -- done between April 21st and 25th of a national sample of 1,000 registered voters, with a 3 point margin of error.
It shows that Joe Biden has assumed a 6 point lead over Donald Trump in the 2020 race for president (44% to 38%). That's quite different from how these men were seen by voters just a few months ago. In December, this poll had Trump with a 3 point lead (44% to 41%).