The Change Research/CNBC Poll, conducted Aug. 7-9, indicated Biden continues to hold a clear lead in Florida, Michigan, Pennsylvania and Wisconsin, and a slim one-point advantage in Arizona.
Trump, however, has a razor-thin lead in North Carolina.
In the national ballot, the survey found Biden has a six-point lead, 50% to 44%, the latest in a string of polls that have Biden on top.
Democrats also maintain advantages in a slew of Senate races. Mark Kelly leads Martha McSally by six points in Arizona, Gary Peters is ahead of John James by three points in Michigan and Cal Cunningham leads Thom Tillis by five points in North Carolina.
Just 46% approve of Trump's job performance in battleground states, and only 44% approve of his handling of the coronavirus pandemic as the US continues to be the hardest-hit country.
Voters in swing states, however, are split 50-50 on who would do a better job handling the economic recovery from the pandemic.
The online poll was conducted with 2,701 likely voters.