JD Vance is having a rocky rollout. How much does it matter to voters?

Republicans and Democrats agree: Ohio Sen. JD Vance has had a rocky rollout as former President Donald Trump's running mate. What's less clear is how much it matters to voters.

Since Vance was picked to join Trump on Republicans' ticket, he's been hit with a cascade of stories about past comments regarding childless women, stringent abortion stances, dislike of police and more. The drip, drip, drip has given Democrats an opening to peg Vance and Republicans at large as "weird," phrasing that has become a cornerstone of Vice President Kamala Harris' messaging.

Yet while the remarks are driving a prolonged news cycle, Vance is running in a cycle when his running mate is a former president famous for sucking up political oxygen and his Democratic counterpart will be picked by a likely nominee who herself was chosen as her party's candidate in an unprecedented series of events.

"It's hard to say," one source close to Trump's campaign said when asked how much voters will care about Vance's introduction. "I don't know if a vice presidential candidate ever is the driver of why someone votes for the principal. And so, that is to be determined."

The conventional wisdom is that running mates historically don't move the needle with voters in presidential races despite the intense calculus equation done by each presidential candidate to pick the right person. The most recent time a pick threatened a ticket was in 2008, when then-Alaska GOP Gov. Sarah Palin found herself in hot water as John McCain's running mate, though the two also ran at a time of terrible poll numbers for outgoing President George W. Bush.

Vance was picked after a weekslong search among several contenders, keeping both the media and much of the GOP in suspense as to who will join Trump on Republicans' ticket.

The Ohio senator was rolled out as the nominee the first day of the GOP convention to much fanfare, and after the confab ended, was immediately hit with headlines over his past comments, many of which focused on his remarks on women without kids, including saying in 2021 that the country was being run by "a bunch of childless cat ladies who are miserable at their own lives and the choices that they've made."

The controversy has pushed Vance to play defense, arguing that "the media wants to attack me" and that reporters are too focused on "sarcasm."

But at the end of the day, it's still the Trump show, Republicans argued, and support for the GOP ticket likely hinges on his appeal.

"Generally speaking, the vice presidential candidates don't typically matter too much, especially when you have a candidate on the Republican side like Trump, who is the lightning rod, is the icon. A lot of voters are going to be voting for Trump. I just don't buy much stock into somebody would have been a Trump voter and is now going to pull off of Trump because of the JD Vance pick," said GOP pollster Robert Blizzard.

Republicans likened the headlines over Trump's past comments as inside baseball rather than a campaign earthquake.

"They call him weird and all that stuff, this is rollout stuff. It's just inside pollster, baseball stuff. When they find out that's not working, the campaign will have moved on," said a second source close to Trump's campaign, arguing that Vance will maintain his appeal to voters in the Rust Belt given his roots in the region.

Trump himself said on Wednesday at the National Association of Black Journalists conference that "you have two or three days where there's a lot of commotion … and then that dies down."

The former president's comments seemed particularly prescient Thursday, when the news cycle was dominated by his questioning during the NABJ interview of Harris' race -- rather than Vance's comments about childless women.

Beyond that, headlines about Vance are competing with news stories about the Democratic ticket.

Democrats are locked in a whirlwind of their own, with Harris jolting to the top of the ticket after President Joe Biden ended his own campaign. She will soon pick her own running mate, which will likely set off a whole new news cycle.

And that's on top of other national discussions, including over the recent assassination attempt on Trump.

"It's just been such a chaotic, turbulent time period that I'm not sure many voters have really homed in and focused on it," Blizzard said.

In addition to the cavalcade of stories, Vance has still been able to raise money and sell out events on the campaign trail, and print copies of his novel "Hillbilly Elegy" and a movie based off of it have spiked in popularity, suggesting some voters are also digesting a more positive depiction of him.

And through it all, Vance is expected to have the full support of the Trump campaign.

"President Trump is thrilled with the choice he made with Senator Vance to be his running mate, and they are the perfect team to take back the White House," Trump campaign spokesperson Karoline Leavitt said in a statement.

That doesn't necessarily mean Vance's introduction on the national ticket has been smooth.

Even those close to the Trump campaign admitted Vance's rollout hasn't been ideal, and a 538 average of polls gauging Vance's popularity found the Ohio Republican's disapproval rating at almost 38%, while his approval rating sat 6 points under that, at 32%.

"This has been, statistically speaking, the single worst rollout of the last 100 years," the first source close to the Trump campaign said. "It makes Sarah Palin look like a f------ Mensa candidate."

That has Democrats sensing an opening.

The universe of undecided voters is small but critical, and it's unclear what factors could persuade someone still on the fence -- particularly if the two people at the top of each ticket remain unpopular.

"Political people who work in politics, I think, are much too dismissive of the impact of a vice presidential pick. Swing voters are extremely low-information, they have often very contradictory views. The notion that they would not decide on who they're going to vote for based on the second-most important person in the world is, frankly, absurd," said one source familiar with the Harris campaign's strategy.

"Political professionals and pundits who dismiss the impact of a vice presidential pick as not possibly factoring into a swing voter's calculations for who they're gonna vote for need to watch some focus groups of swing voters."

Harris' campaign and its allies are already seizing on the "weird" attack lines. The language is dominating surrogate interviews on cable news, and Vance's comments are the frequent focus of press releases.

Democrats also said the line of attack layers onto existing messaging over "freedom," including on abortion and families' rights to make decisions for themselves.

And if upcoming polling showing the attack sticking, the rhetoric is expected to become a mainstay of the race.

"The Democrats just need to continue bottling up and holding up a mirror to them," one Democratic pollster said. "Harris and her running mate are going to be speaking about what the polling says is critical to get them to 270" Electoral College votes.

"Keep paying the opposition researchers, is what I would suggest," the person added. "Because it's not like he's only said three controversial things in the last 10 years."