Democrats have no Senate seats to spare. One of their indispensable seats is occupied by Arizonan Kyrsten Sinema, who has so angered supporters back home they’re gearing up to replace her when she comes up for reelection in 2024 (read story here). They have many complaints against her, but nothing infuriated them more than her manner of casting this vote against raising the federal minimum wage:
The only thing that matters is if she can win against a Republican. There are the dangers of primarying a sitting Senator in a state that until the last couple cycles was strongly Republican.
Voting against her party also matters, and it’s ludicrous to suggest otherwise. It’s not a given that primarying her would return the seat to Republicans. The Arizona GOP is badly divided, and doesn’t have a quality candidate in the wings.