A plurality of independents, 44 percent, approve of Biden’s choice, greater than the 27 percent who disapprove. But more than 1 in 4 independents, 28 percent, have no opinion.

Another poll conducted immediately following Biden’s choice, an ABC News/Ipsos survey released early Thursday, also shows more voters calling the pick “excellent” or “good” (47 percent) than “not so good” or “poor” (29 percent).

After naming his running mate 12 weeks before Election Day — and even closer to the beginning of early voting in some key states next month — Biden enters the final sprint in a position of strength. The latest Morning Consult national tracking poll shows him 8 points ahead of Trump, 51 percent to 43 percent. That matches his 7½-point lead in the RealClearPolitics polling average.

In the POLITICO/Morning Consult flash poll, voters are divided on whether Biden’s choice of a running mate will affect their vote. Nearly half, 49 percent, say it will have no impact. But a quarter say it will have a major impact, and 2 in 10 say it will have a minor impact.

There is less partisan disparity on that question than on others: 40 percent of Democrats, 63 percent of Republicans and 45 percent of independents say Harris' selection won’t have an impact on their vote.

Meanwhile, Trump’s precarious standing with voters continues to put his reelection in peril. In the POLITICO/Morning Consult poll, his approval rating is just 39 percent, matching his favorable rating. Notably, his favorable rating trails both Biden’s (51 percent) and Harris’ (45 percent).

Both Biden and Harris appear to have gotten a bounce in personal favorability numbers from the announcement. Biden’s 51 percent favorable rating is the highest mark for the former vice president recorded in POLITICO/Morning Consult surveys since he became the presumptive Democratic nominee.

In the flash poll, Harris’ 45 percent favorable rating leads her 37 percent unfavorable rating. In a late July POLITICO/Morning Consult poll, voters were evenly divided: 33 percent rated her favorably, and 34 percent had an unfavorable opinion of her.

“Following his selection of Sen. Kamala Harris to be his running mate, former Vice President Joe Biden’s favorability has hit its highest point in our tracking since June. The California senator is well known and viewed in a favorable light by likely voters — including minority voters who are key to the ticket’s hopes of beating President Donald Trump and Vice President Mike Pence this fall,” said Kyle Dropp, co-founder and chief research officer at Morning Consult.

Biden’s positions during the presidential primary, which roughly fall within the mainstream of his party, drew skepticism from progressives, who hoped Biden would choose a running mate to his left on the ideological spectrum. But voters in the flash poll rated Biden and Harris roughly evenly on a 7-point ideology scale: 29 percent rate Biden as a “1,” or “very liberal,” while 30 percent give Harris the same rating.

Trump, meanwhile, is viewed as more extreme. More than 4 in 10 voters, 42 percent, rate him a "7" on the 7-point scale, for "very conservative." And another 20 percent rate Trump a "6."

The POLITICO/Morning Consult flash poll surveyed 1,990 registered voters. The margin of error is plus or minus 2 percentage points, though polls conducted entirely in one day can contain additional sources of error.

Morning Consult is a global data intelligence company, delivering insights on what people think in real time by surveying tens of thousands across the globe every single day.

More details on the poll and its methodology can be found in these two documents: Toplines | Crosstabs