"Ms. Harris is ahead of Mr. Trump by four percentage points in Wisconsin, Pennsylvania and Michigan, 50 percent to 46 percent..."

"... among likely voters in each state. The surveys were conducted from Aug. 5 to 9.... On question after question, the poll finds that voters don’t seem to have major reservations about Kamala Harris, Nate Cohn writes."

The NYT reports.

At the Nate Cohn link, the key point seems to be that Biden was a terrible candidate:

Views of Mr. Trump haven’t diminished. In fact, his favorability rating ticked up slightly, to 46 percent across the three states — just enough to represent his highest rating in the history of Times/Siena polling. It’s a tally that might have been enough for a clear lead against Mr. Biden, whose ratings had fallen into the 30s in early July. But for now it’s not enough against the surging Ms. Harris.

One way to think about her position is that she has become something like a “generic” Democrat. This might sound like an insult, but it’s really not. In fact, nothing is more coveted. An unnamed generic candidate — whether it’s a Democrat or a Republican — almost always fares better in the polls than named candidates, who are inevitably burdened by all the imperfections voters learn about in the process of a campaign....

On question after question, the poll finds that voters don’t seem to have any major reservations about her.... A majority doesn’t think she’s too far to the left, either: Only 44 percent of likely voters say she’s too liberal or progressive.... Ms. Harris may be polling like a generic Democrat, but she’ll now be subject to much more scrutiny and attack. To this point, she’s benefited from a few weeks of very favorable media coverage....