Manchin is in trouble in West Virginia.
Just like Sinema is despised in Arizona
She was censured by the Arizona Democratic party over her over her opposition to changing the filibuster
One of the main reasons she switched to Independent was because she was going to face a primary challenger in 2024 and would likely have lost.
BTW - Before she got the awesome money making gig as Senator she was on the record in opposition of the filibuster and even ripped on "independent" Senator Joe Lieberman