The fact that Joe Manchin is allowed to continue calling himself a member of the Democratic Party is a condemnation of that party and confirms to me that their “failures” are actually deliberate controlled opposition.
No self respecting political party with a policy platform it wants to impose would allow this. It doesn’t even have anything to do with the specifics of the policy, this is something that any political party who actually wants to legislate, for good or for evil, should follow.
You don’t allow members of your party to consistently vote against your policy platform. If they do that, you strip them of any powers you’ve given them, kick them out of your party, and run an opponent in their district with more funding than any other race in the country.
The republicans would not allow one of their members to constantly destroy their major platform items like this, because they are a serious political endeavor with goals they intend to accomplish. The Democrats are not, they are controlled opposition whose only goal is to lose, lose bad, and lose frequently, and that is the only reason they would allow this to continue.