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.

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

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.