There are some other things transpiring in American politics right now. But we must note that Democratic leaders are now unabashedly stating what Bernie Sanders supporters said over and over in 2020: the party pushed Joe Biden primarily to stop Bernie.
I think they just know that they’re not the voices that could ever convince Joe Biden’s ego to stand down, and if he holds on they’d be the ones to suffer most for rebellion.
I think the word you are looking for here is “cowards”