I think we can still lay this on at the feet of the party as a whole. They have time and time again used "Vote Blue No Matter Who" to push through the worst candidates while scolding voters for wanting better. All while blacklisting progressive candidates who defeated weak incumbents.
Who replaced manchin? A Democratic socialist? A progressive? I'll give you a hint:
Do you really think the people of West Virginia are clamoring for progressive change but are being surpressed by the DNC?
The Democratic party has spent decades responding to Republican hate and bigotry with "they probably have a point but you shouldn't vote for them" so yeah of course he was replaced with someone worse. That is what happens when you constantly concede ground to bigots.
Google "Paula Jean Swearingen" and "Zack Shrewsbury." Then we can review if we could have done better than Manchin, who voted for more Biden judges and bills than any Republican would. Then we can analyze Sherrod Brown's Ohio loss. Then we can review the history of resource extraction in the US.
I think they must be a gang of toothless inbred hillbillies. Look at the kind of fuckers they KEEP electing.