At this point, if there is any shred of hope left to convince Manchin to change his stance, it would have to come from West Virginians.
The thing, say those who know Manchin, is that he doesn’t care about that criticism. “Joe Manchin doesn’t give a fuck about progressive backlash or caucus politics,” said someone familiar with Manchin’s thinking. “Just West Virginia.”source
This means that the Democrats, and pretty much everyone else that still believes in democracy, would have to work together to convince West Virginians first. He has absolutely no interest in listening to anyone else.
For Sinema, on the other hand, it would be on Democrats to find her financial donors, and apply pressure on them to stop financing her, and Arizonans to be publicly vocal with her.
Other than that, people ought to find who Manchin is deflecting away from and get definitive stances on the filibuster form Democrats like:
Hickenlooper, I have yet no idea what to do about his stance yet, but more noise needs to be made.
Every Democrats needs to be on record stating where their stance is on HR1 and the filibuster.
Going forward, there needs to be concentrated effort in increasing voter turnout. There is a small possibility that very high voter turnout could complicate voter suppression efforts – after all, Republicans were attempting to suppress voter turnout before and during the 2020 elections and Georgia special elections. And not just at the federal level, Democrats need to work like hell to take back state legislatures.