Who is Mark Kelly? Get to know Arizona’s senior senator

After Vice President Kamala Harris became the presumptive Democratic presidential nominee in July, Arizona Sen. Mark Kelly was listed by betting websites as the leading contender to join Harris’ ticket.

That never happened, as Harris picked Minnesota Gov. Tim Walz and then lost the election handily to Donald Trump. But as the second Trump administration takes over and the balance of power swings to Republicans in Washington, Kelly is drawing attention for both his intense objection and acquiescence to the latest GOP moves.

In a hearing, he skewered Trump’s pick to lead the Department of Defense, Pete Hegseth, for his alleged history of getting sloppy drunk and taking young female staffers to strip clubs. But Kelly was also one of 10 Democratic senators to back the GOP's controversial Laken Riley Act, which allows for deportations of undocumented people merely accused — not convicted — of crimes. That move drew criticism from local-level Democratic officials like Phoenix councilmember-elect Anna Hernandez.

Here’s what you need to know about Arizona's senior senator, who is feeling the crunch in Trump’s Washington.

Who is Mark Kelly?

Prior to being elected to the Senate in 2020, Kelly was an astronaut at NASA and traveled to space on four separate missions from 2001 to 2011, spending more than 50 days in space. When he was selected to join NASA in 1996, he was in the same class as his identical twin brother, Scott.

Before his days at NASA, Kelly was a U.S. Navy pilot. He joined the service in 1986, the same year “Top Gun” was released, and later flew 39 missions in Iraq during Operation Desert Storm. He has degrees from the U.S. Merchant Marine Academy and the U.S. Naval Postgraduate School, where he studied marine and aeronautical engineering.

He is also the husband of former Rep. Gabby Giffords, whom he married in 2007. Giffords survived a 2011 shooting during a campaign event in Tucson that killed six people. After Kelly commanded his final mission to space months later, he retired from NASA to spend more time helping Giffords rehabilitate. He and Giffords became notable advocates for solutions to prevent gun violence, such as background checks, and Giffords founded an eponymous organization dedicated to those efforts.

Kelly was elected to the Senate in 2020, defeating Martha McSally in a special election after the 2018 death of Sen. John McCain. Kelly won a full term in 2022, handily beating Republican challenger Blake Masters.

Mark Kelly’s record in the Senate

According to FiveThirtyEight, Kelly voted in line with President Joe Biden 95.5% of the time during the 2021-2022 congressional session. They disagreed on vaccine and mask mandates, which Biden supported and Kelly did not; and on imposing more sanctions over a Russian gas pipeline, which Kelly supported and Biden opposed.

Kelly has sponsored a combined 65 bills in four years, according to Congress.gov. Four passed the Senate to later die in the House of Representatives, while two became law. Both of those bills that passed were from the 2021-22 session and dealt with water rights for Indigenous tribes in Arizona and near the Colorado River.

Kelly also has co-sponsored 801 bills in the Senate, 26 of which were signed into law by Biden. Nine of those were laws that passed during the 2023-24 session. The most notable was the END FENTANYL Act, which requires border patrol to more frequently review and update manuals and policies. It was co-sponsored by Republican Sens. Rick Scott of Florida and Mike Braun of Indiana.

In the previous session, Kelly co-sponsored bipartisan bills that required law enforcement agencies to conduct de-escalation training, reformed ocean shipping and promoted U.S. exports, countered human trafficking and extended a program that compensates people who were exposed to radiation from atomic weapons testing.

Kelly and Sen. Jon Tester, a Montana Democrat, also introduced legislation to require members of Congress to post their public schedules online so constituents can have a more transparent look at what their elected officials are up to and with whom they’re meeting. It has not gained traction.

Kelly’s willingness to work across the aisle with Republican colleagues aligns with his appeal to centrist and center-right voters, who played a crucial role in electing Kelly in 2020 and reelecting him in 2022.

One reason Harris might not have picked Kelly as a running mate in 2024 was because of unions’ concerns about him. Last summer, ABC’s Max Zahn reported that unions, a major player in the Democratic Party’s coalition, seemed to have an issue with Kelly for not backing the Protecting the Right to Organize Act. But Kelly’s team moved quickly to quell the fire – about an hour later, Kelly said he would vote for the bill.

“I would vote for it today,” Kelly told HuffPost. “I am, like a lot of legislation, working to make it better. But if it came to the floor today or any day going back to the day I was sworn in, I would vote for it.”

The AFL-CIO, a federation of some of America’s largest unions, has noted Kelly voted in favor of working people 98% of the time during his first three years in the Senate.