Sen. Mark Kelly (D-Ariz.) has risen to near the top of the list of possible running mates as Vice President Harris considers whom she wants to run alongside her.

Kelly has been sent vetting materials as one of a handful of Democrats under consideration for the role. A veteran and former astronaut, Kelly brings a background that is unique compared to other possibilities being considered.

He also enjoys strong popularity in his purple battleground state of Arizona, one that could help decide the winner of the November election.

“I think you need someone that’s got national ID and has been tested to a degree, and I think [Kelly] brings that,” said Democratic strategist Matt Grodsky, a former communications director for the state Democratic Party.

Democrats have expressed enthusiasm around Kelly since he first won his Senate seat in a 2020 special election to serve the remainder of the late Sen. John McCain’s (R-Ariz.) term. He was then elected to a full term in the Senate in 2022. 

In both cases, he won by a few points and performed better than President Biden in the state in 2020 and now-Gov. Katie Hobbs (D) in 2022. 

Strategists and other observers said Kelly’s ability to perform well in a swing state demonstrates a political prowess that could carry over to other key states outside Arizona. 

Kelly served in the Navy and took part in dozens of missions in Operation Desert Storm during the Persian Gulf War before being selected as an astronaut for NASA, according to his biography on his Senate website. He traveled into space four times and retired in 2011. 

Grodsky said Kelly’s background gives him a certain “legitimacy” to be able to speak about issues concerning the military, national defense and foreign policy that other choices don’t have and could bring added crossover appeal to the ticket. 

“That does have appeal across the aisle, with moderate Republicans, independents, people that are in more of that John McCain mold, which I think is crucial not just for picking up Arizona or swing state votes but across the country,” he said. 

Kelly has brushed off the “veepstakes” speculation around him but did not rule out being open to serve as Harris’s running mate if he were offered the role. 

“This is not about me. But I’ve always, always, when I’ve had the chance to serve, I think that’s very important to do,” he told reporters on Thursday. 

Kelly has also caught attention for slamming Sen. JD Vance (R-Ohio), who is the GOP running mate, over various issues, including Vance’s position on Ukraine and comments the Ohio senator made in 2021 that “childless cat ladies” were running the country. 

Kelly is one of several Democratic names that has received attention about potentially joining Harris, a group that includes Pennsylvania Gov. Josh Shapiro (D), Kentucky Gov. Andy Beshear (D) and North Carolina Gov. Roy Cooper (D). 

Kelly has received praise from some of his Senate colleagues. Sen. Chris Van Hollen (D-Md.) emphasized Kelly’s ability to bring in voters outside the Democratic base in a key swing state. 

“That’s a record that you want, somebody who’s been able to show that ability to get votes, enthusiasm among Democrats, but also votes beyond that,” he said. 

Sen. Bob Casey (D-Pa.) said Kelly is an effective and capable senator whose “strong” national security background would help in improving Democrats’ chances in battleground states including Pennsylvania. 

Both of Kelly’s electoral victories illustrated his ability to bring in more voters to his coalition. He was able to flip the populous Maricopa County in 2020, as did Biden that year, after the county voted for Republican candidates for decades. 

In 2022, Kelly won reelection by nearly 5 points, carrying two congressional districts that elected Republicans to the House. 

Strategists said Kelly’s record on policy explains his appeal. 

Democratic consultant Adam Kinsey, a former executive director of the Pima County Democratic Party in Arizona, said Kelly is in a “unique” position to be able to discuss the issue of border security as a senator who comes from a border state and pushed for the immigration bill that Senate Democrats and Republicans agreed upon. 

It briefly appeared that the legislation had a chance to move forward, but after former President Trump came out against it as a “catastrophe waiting to happen,” it failed. Democrats have seized on Trump’s opposition to the bill as evidence that Trump wants to run on the issue of immigration, a potential vulnerability for Democrats, more than solve it. 

“Mark is in a great position to expose that, say, ‘Look, I represent the border state down there. I’m very aware of what’s going on,’” Kinsey said. “And I think it really gives him, it gives Democrats sort of a way to really have somebody who’s an expert on the situation speak authoritatively.” 

Kelly also has a personal connection to political violence, an issue that has gained renewed attention in the aftermath of the shooting at Trump’s rally earlier this month. Kelly’s wife, former Rep. Gabby Giffords (D-Ariz.), was shot in the head in 2011 in Tucson, an event that received widespread national attention. 

Giffords and Kelly founded a nonprofit organization to support gun control measures soon after the shooting, and Kelly has advocated for measures like enhanced background checks and red flag laws. But he is also a gun owner and sought to position himself as a supporter of the Second Amendment despite his calls for reform. 

“There’s the narrative that Republicans often try to use against Democrats of the ‘gun grabbers,’” Kinsey said. “That’s not Sen. Kelly. He’s not cut from that cloth, but he is very passionate about gun safety.” 

At the same time, one potential drawback may be that if elected, Kelly would leave his Senate seat, requiring the governor to appoint an interim replacement and a special election in 2026 that Republicans may be able to win. That could be especially perilous with Democrats already holding such a narrow majority in the Senate. 

But he may still be deemed the right choice for the current moment. Kelly was also particularly effective at raising large amounts of money, taking in about $90 million during his 2022 campaign. 

“You’ve got somebody with, frankly, the gravitas, legislative record of Mark Kelly, really compelling backstory and the ability to raise money and match up against these guys on the other side, he looks like the best choice,” Kinsey said.