On Thursday, Arizona Rep. Kyrsten Sinema announced that she would seek the Democratic nomination to challenge GOP Sen. Jeff Flake. Sinema's decision has been expected for some time, and the DSCC endorsed her the following morning. Sinema also quickly earned an endorsement from EMILY's List, an influential group dedicated to electing pro-choice Democratic women. If Sinema wins, she will be the first openly bisexual person elected to the Senate, a distinction she already holds in the House.
Sinema, who has represented a Tempe-area seat for three terms, had $3.2 million in the bank at the end of June, more than Flake's $3 million war chest. Sinema has spent years considering a bid for statewide office in this light red state, and the former Ralph Nader supporter has developed a reputation as a centrist in the House. Notably, Sinema voted against Nancy Pelosi in the 2015 and 2017 speakership elections, symbolically casting her vote instead for other Democrats. Sinema has also argued that national Democrats are moving too far to the left, and she said that it's "just not real" to promise single-payer health and free college.
It's possible that Sinema could be vulnerable in a primary, but there doesn't seem to be a credible opponent on the horizon. A few other Democrats have already announced that they'll challenge Flake, but none of them have much name-recognition or outside support. State Rep. Randy Friese has said he was leaning toward running. However, while Roll Call's Bridget Bowman reports that Friese planned to run if Sinema didn't announce by Oct. 1, she says he told people he'd reconsider if she got in.
Trump carried Arizona 48-45, and Flake is a top Democratic target. Flake has been one of Trump's most vocal critics in the GOP while voting with him on most major issues, and he may have managed to just piss off voters from across the political divide without making many friends in the process. Flake faces a primary challenge from ex-state Sen. Kelli Ward, who lost her 2016 bid against Sen. John McCain 51-40, and a few recent polls show him badly losing. The local GOP pollster HighGround Public Affairs also recently found Flake losing a hypothetical general election to Sinema 41-33, while a poll for the Democratic group Senate Majority PAC had him down 47-40.