This is the biggest problem with dems. They often don't want to step on toes or throw their weight around to get something good passed. To dems an "ok bill" passed with people happy is better than a really good bill passed with a lot of pissed off people. Some of the dem senators need to be squeezed. Just out-right squeeeeezzzzzzzed. How? Demote their committee positions. Don't raise money for them. Make their life very difficult.
The GOP are masters at this. They squeeze the crap out of the rank and file for big legislation. Can dems do that? Not with statements like "we've got to pass something."