Sen. Kyrsten Sinema’s (I-AZ) decision not to seek reelection to the Senate puts Rep. Ruben Gallego (D-AZ), the likely Democratic nominee, and Kari Lake, who is the front-running Republican candidate, on the fast track for a two-way race in Arizona.

Immediately following the news of Sinema’s retirement, Sen. Steve Daines (R-MT), the leader of the GOP Senate campaign arm, declared the development would improve Lake’s opportunity to flip the seat. 

Senate Republicans had been nervous about the possibility of a three-way race between Lake, Sinema, and Gallego after polling suggested Sinema could siphon away twice as many Republican voters as Democrats in a state that is 34% Republican, 34% independent, and 30% Democratic, according to Arizona data. Lake is still facing a primary against Pinal County Sheriff Mark Lamb, but she is seen as an overwhelming front-runner.

“An open seat in Arizona creates a unique opportunity for Republicans to build a lasting Senate majority this November,” Daines said in a statement. “With recent polling showing Kyrsten Sinema pulling far more Republican voters than Democrat voters, her decision to retire improves Kari Lake’s opportunity to flip this seat.”