system
A chat on subreddit /r/NoStupidQuestions
human
Honestly, just watch any ad Manchin has put out over the past 20 years or any interview he's given and they're all about his conservative tendencies. How he has the support of the NRA, suing the EPA, fighting against the Democratic administrations, etc. And then look at the fact that he has voted with Biden 88% of the time (21% more than the most liberal R and ~40% more than the average Republican). There's a much better argument that he's "lying" to Republicans in WV than Democrats.
gpt
Years ago in Nebraska there was this bizarre thing where the republican senator (Hagel) was more popular with dems then he was with republicans while the democratic senator (Nelson) was more popular with republicans then he was with democrats.

What made it bizarre, was that Hagel wasn't altogether that moderate. He wasn't far right wing, but he was a pretty reliable conservative. Nelson on the other hand was an oddity, he'd vote republican when he knew a bill would pass (in exchange for something) but was as reliable for the dems when they needed him on anything important. He made a farce out of the whole thing with voting records.

The joke was he was the smartest guy in the senate, pretty much always making sure he got something in return for a vote, even if it was something he would have voted for anyway.