Harris VP pick: Here’s how Americans feel about Tim Walz

Update 10:40 a.m. EDT: Vice President Kamala Harris officially announced Minnesota Gov. Tim Walz as her running mate Tuesday. Harris said in a post on X that Walz has "delivered for working families like his."

Vice President Kamala Harris has officially announced her pick for running mate and many Americans don't know much about him, according to the latest PBS News/NPR/Marist poll.

About 7 in 10 Americans say they don't know Gov. Tim Walz well enough to have a positive or negative opinion of him.

READ MORE: 5 things to know about Tim Walz, Kamala Harris' VP pick

Given the breakneck pace of American politics lately, the Democratic ticket has enough time to make an impression in the 90-some days left before Election Day, Republican strategist Olivia Troye said.

Here's how Americans see a few of the veepstakes names that were in consideration.

Tim Walz

Minnesota Gov. Tim Walz has served in the military and as an educator, though right now he might be best known nationally for calling Donald Trump, the Republican presidential nominee, "weird." Overall, few Americans appear to know much about him, according to this latest poll.

WATCH: Minnesota Gov. Walz says GOP 'playing with fire' by 'demonizing' Harris

• 71 percent of U.S. adults said they are unsure of who Walz is or have never heard of him.
• 17 percent said they view him favorably.
• 12 percent view Walz unfavorably.

Mark Kelly

Sen. Mark Kelly, D-Ariz., has been to space. Could he now reach the other side of Pennsylvania Avenue? Kelly performed the best of the Democratic VP candidates considered in this poll.

• 31 percent of U.S. adults said they have a favorable impression of Kelly.
• 18 percent hold an unfavorable view of him.
• About half – 52 percent – said they are either unsure who he is or have never heard of him.

Josh Shapiro

Among the Americans who have heard of Pennsylvania Gov. Josh Shapiro, opinions were fairly split.

• 25 percent of U.S. adults said they have a favorable impression of Shapiro.
• 23 percent hold an unfavorable view.
• 53 percent are unsure or do not recognize his name.

Where does Harris stand with voters?

Since late July, when Biden left the 2024 race, Harris' favorability has increased 6 percentage points. Her unfavorability has also risen.

• 46 percent of Americans say they have a favorable impression of Harris. That includes nearly all Democrats (87 percent) and 44 percent of independents.
• 48 percent of Americans hold an unfavorable impression, up 4 percentage points from last month. That includes 91 percent of Republicans and 49 percent of independents.
• About half of people of color say they view Harris favorably, including 72 percent of Black Americans. By comparison, 43 percent of white Americans felt the same way.
• Among white women who went to college, 61 percent said they have a favorable view of Harris.

The difference between those with favorable impressions versus unfavorable impressions — 2 percentage points — falls within the margin of error.

According to Troye, the past couple of weeks alone – an assassination attempt on former President Donald Trump's life, President Joe Biden leaving the race – have shown just how dynamic American politics can be.

"It's a completely different election" now, Troye said.

WATCH: A look at Kamala Harris' legal career and political record

Democratic strategist Adam Parkhomenko said Harris' team is running a campaign with "gloves off" and they are systematically responding to Trump's attacks during rallies and interviews.

Parkhomenko said "The party is more united behind her than I've seen" in terms of getting behind whomever Harris thinks is the right choice for her running mate.

He expects the American public to get interested in the Democratic National Convention in Chicago, where Harris and other prominent members of her party will share their agenda later this month.

"We'll see the [poll] numbers change coming out of there," Parkhomenko said.

What about Trump and JD Vance?

Enthusiasm for Trump appears to have fallen since late July, despite the former president's harrowing experience surviving a deadly shooting at a campaign rally, followed immediately by a national convention where allies, former rivals and celebrities cast their support for him with unfettered fervor.

• 44 percent of U.S. adults said they hold a favorable impression of Trump, up 1 percentage point since July and well within the margin of error. That includes 89 percent of Republicans and 37 percent of independents.
• 53 percent of Americans view him unfavorably, up 4 percentage points from 49 percent last month. This includes 89 percent of Democrats and 61 percent of independents.
• 46 percent of white Americans said they have a favorable view, compared to 29 percent of Black Americans who feel the same way.
• Six in 10 white men who did not graduate from college view Trump favorably.

Troye said she thinks there's a larger portion of the Republican voting base that is moderate and doesn't identify with the MAGA movement.

More people now know who Ohio Sen. JD Vance is compared to last month, but that isn't a wholly positive development for his candidacy.

• 43 percent of Americans view Vance unfavorably, up from 31 percent in July.
• 34 percentview him favorably, an increase from 28 percent last month.
• 23 percent of Americans said they were unsure of who Vance is or had never heard of him, a substantial decrease from 41 percent last month.

In the weeks since Trump named Vance as his running mate, the politician and author's past words have come back to haunt him, including a 2021 interview on Fox News where he said that women like Harris who have not given birth "are childless cat ladies who are miserable with their own lives."

"The more that America gets of JD Vance, the more they seem to not like him," Parkhomenko said.

PBS News, NPR and Marist Poll conducted a survey on Aug. 1 through 4 that polled 1,613 U.S. adults with a margin of error of 3.3 percentage points, 1,513 registered voters with a margin of error of 3.4 percentage points, 1,309 registered voters who definitely plan to vote in November's general election with a margin of error of 3.7 percentage points and 717 Democrats and Democratic-leaning independents with a margin of error of 4.9 percentage points.