Much of the newfound Democratic strength stems from improved voter perceptions of Ms. Harris. Her favorability rating has increased 10 percentage points among registered voters in Pennsylvania just in the last month, according to Times/Siena polling. Voters also view Ms. Harris as more intelligent and more temperamentally fit to govern than Mr. Trump.
...
Still, there is little doubt that replacing Mr. Biden on the ticket has turbocharged Democratic enthusiasm about the election. Among Democrats, voter satisfaction with their choice of candidates has skyrocketed since Ms. Harris entered the race, up 27 percentage points in the three swing states since May, according to the latest Times/Siena results. Democrats are now more likely to say they are satisfied with their candidate choices than Republicans, a reversal from three months ago, when the question was last asked.
...
In the three battlegrounds, Ms. Harris is in a stronger position than Mr. Biden was in May with most demographic groups, including white voters without a college degree. She is faring better with key parts of the Democratic Partys coalition that had begun to erode under Mr. Biden, most notably Black and young voters. But she also appears to be holding on to older voters, who were some of the presidents most ardent supporters.
The share of voters who said they trusted Ms. Harris to handle economic issues was higher than the share Mr. Biden received in May, though she is still nine points behind Mr. Trump on an issue where the Republican nominee has long held the advantage. And she has a 24-percentage-point advantage when it comes to whom voters trust to handle abortion, an issue considered one of the strongest for Democrats in May, Mr. Biden held an 13-percentage-point advantage on abortion.
Mr. Trumps attacks on Ms. Harris as not smart and incompetent have not landed with most voters. Nearly two-thirds of voters see Ms. Harris as intelligent, more than say the same about Mr. Trump. A majority of white voters without a college degree a demographic that typically favors Republicans said Ms. Harris was intelligent.
There's more. Largely encouraging with some points of caution
538.com rates them the best/top 3. So it's pretty good information.