Ruben Gallego
Rep. Ruben Gallego and Sen. Kyrsten Sinema were rising stars within Arizona Democrats at the same time — then turned rivals. Jonathan J. Cooper/AP

What the Kyrsten Sinema-Ruben Gallego Rivalry Means for the Future of the Senate

Sinema is leaving the Senate. If Gallego takes her place, he will be a very different senator.

If Democrat Ruben Gallego wins the Senate seat Kyrsten Sinema is departing this fall, it will be the culmination of a yearslong political rivalry between the pair. It will also give the Democratic caucus something Sinema is admittedly not: a fully fledged team player.

Gallego and Sinema, who served in the Arizona state legislature together about 15 years ago, have a long-running distaste for each other, according to more than a dozen sources who know them well, all of whom requested anonymity to speak frankly about the pair. It’s grown as they’ve risen in national politics and, as one House member put it, it was “inevitable” that the two would one day face off against each other — though in the end, it was Sinema who bowed out after a dramatic fall from political stardom.

Their differences are partly about politics — Sinema shifted toward the center, while Gallego has been more consistently progressive — and partially due to their style. Sources told NOTUS that Gallego focuses on relationships more than Sinema does, which could illustrate how he would legislate in the U.S. Senate.

“Kyrsten was always much better at understanding and leveraging power than Ruben ever was,” a former mutual friend said. “I don’t think he is as worried about actually getting things done legislatively as he is concerned about building relationships and getting people to like him. … He is somebody that doesn’t have as much success legislatively, but he is fundamentally more well-liked than she has been in Congress.”

Spokespersons for Sinema and Gallego declined to comment for this story.

Sinema and Gallego were rising stars in the Arizona Democratic Party starting before the 2010s. Their relationship soured when they worked together on a campaign against a ballot initiative to prohibit gay marriage and deteriorated further while they were serving in the state legislature, according to sources who know them both well.

Both were popular in their early days in Arizona, Gallego more so among Latinos and veterans, and Sinema with the LBGTQ+ community and establishment Democrats.

Gallego would become more popular among Arizona Democrats over time, due both to personality and policy. Two sources described Gallego as someone who sees himself as a “team player.”

Gallego, a Marine and Iraq War veteran, often talked about how “in the Marines, you didn’t win by yourself. You had to win together,” a friend with both of them, who was involved with advocacy work at the time the two were in the legislature, told NOTUS.

A lawmaker who served with Gallego and Sinema in the state legislature said the division between them widened as Sinema became more moderate in the legislature, a trend that would continue with Sinema at the national level.

“I can tell you they never really saw eye to eye,” the lawmaker said. “I think it was more personality conflicts, but as Sinema moved more to the center and started taking on issues and causes that may not win you a popularity contest in our party, I think that divide became even stronger.”

It was evident, sources said, that neither Gallego nor Sinema had any intention of staying put in the state legislature. They served one term together in different chambers before Sinema was elected to Congress in 2012. Gallego would join two years later, and the two served together until Sinema was elected to the Senate in 2018. Both have sponsored and co-sponsored many pieces of legislation that became law during their time in Congress: more than 100 for Sinema, who has been in Congress two years longer, and more than 60 for Gallego.

In the House, Sinema was viewed as a “pragmatic problem solver,” a Democratic strategist said. While Sinema’s political evolution to moderate started in the state legislature and continued through her time in the House, it accelerated in the Senate.

Kyrsten Sinema, Ruben Gallego
Rep. Ruben Gallego and Sen. Kyrsten Sinema have served together for years as Arizona legislators. Matt York/AP

The strategist said that while Sinema tried to fashion herself as a maverick in the style of John McCain, she did not fully understand what made him successful. McCain would pick key moments to break with his party and would do so on politically popular issues, such as campaign finance reform.

“Sinema definitely paid attention to the branding part of it and using big moments, but where it went wrong for her … she didn’t realize the big moments that she was taking a stand and becoming a household name on, were actually kind of obstructing things that were generally popular,” a Democratic campaign consultant said.

Sinema received so much negative attention that it crossed into pop culture. She became a character on “Saturday Night Live” and the punch line of jokes. Many Democrats grew frustrated with her stances.

“Democrats went from being excited to win that Senate seat in 2018 to having their hopes dashed that we can’t actually do anything,” the campaign consultant said.

While Sinema was becoming less liberal, she also became more detached from the people who had supported her in the past. Before her time in the Senate, Sinema was viewed as responsive. But over time, sources said, it became harder to get in touch with her. One friend said that she kept changing phone numbers.

“She just cut a lot of people off,” the friend said. “And I don’t think people like that.”

Another state lawmaker who served with both said that when she moved to the Senate, she stopped attending Democratic meetings in Arizona and “just kind of went solo really quick.”

Sinema underestimated the importance of maintaining these relationships for her political success.

“The number of people wanting Sinema to succeed has been a diminishing currency for her over her career,” a Democratic strategist said.

As Sinema lost more and more support, it became more likely that she would not survive a primary challenge. She switched her party registration to independent in December 2022, making it even more difficult to hold the seat. Winning as an independent without a “base” is difficult, said a Democratic insider.

“The base is who will go out and bust their ass for you,” the insider said. “She decided that that was not necessary to win. And I think the polling shows you that it is.”

Sinema’s announcement Tuesday marks the likely close of a political career that ended much sooner than anyone anticipated.

“It’s pretty much a stunning fall,” a separate Democratic consultant said. “She was the most popular elected official in Arizona three or four years ago.”

Gallego is expected to win the Democratic nomination in July and will likely face off against Republican Kari Lake for Sinema’s seat. He has castigated Sinema for voting with Republicans and is expected to align himself more closely with the Democratic caucus.

In her speech announcing she would not run for reelection, Sinema conceded that her approach — more focused on compromise and outcomes than political wins — is “not what America wants right now.”

Gallego will now have a chance to show whether his approach is more popular.


Tara Kavaler is a NOTUS reporter and an Allbritton Journalism Institute fellow.