Ruben Gallego to run for Arizona Senate seat held by Kyrsten Sinema

Democratic congressman and ex-marine faces potential three-way race with newly declared independent and a Republican next year

The Democratic congressman Ruben Gallego of Arizona announced on Monday that he will run for the Senate, teeing up a potential battle against incumbent Senator Kyrsten Sinema next year.

Gallego, a marine combat veteran who has served in the House of Representatives since 2015, made the widely expected announcement in a campaign video that was filmed in his Phoenix area congressional district.