Sen. Kyrsten Sinema, a former Democrat turned independent and long a boogeyman for liberals, is retiring this year, and Democratic Rep. Rueben Gallego is facing Republican Kari Lake in a race for the open seat. Gallego, who represents Phoenix and the surrounding western suburbs in Congress, has a fundraising advantage, having raised nearly $22 million through the end of Sept., while Lake has nearly $17 million. 

A polarizing ally of Trump, Lake first ran for governor in 2022 and refused to accept the election results. A CBS News poll conducted from Oct. 11-16 had Gallego leading Lake by 9 points. 

A CBS News poll conducted from Oct. 11-16 in Arizona had Trump leading by 3 points against Harris. Trump is boosted by voters who say immigration/border and the economy are their most important issues, while Harris has advantages with voters who prioritize abortion rights and the state of democracy, keeping this race close.

Polls in Arizona close at 7 p.m. MT (9 p.m. ET).