Because Republicans vote in lockstep but Democrats don’t.
The point that (I think) they’re trying to make is that the democrats always have N+1 politicians who will be the ratfuckers of the party; your Machin, Sinema, Lieberman, etc. No matter how the numbers work out, there always seems to be juuuuust enough ratfuckers in the party that the big legislations never get through without getting the back broken for capital.
I don’t have to propose anything to point out the flaws in the party.
And I’m saying this as someone who generally votes for them. Stop treating every response as if we have to provide some grand solution when pointing out the shit they’re doing wrong. I’m not a policy wonk, so I don’t know the best path forward. But I can still recognize when a bed has been thoroughly shat.