I know that personally, one of my biggest frustrations since Democrats took power has been their lack of party line discipline. When conservatives are in power they’ve proven much better at unifying around the agenda and using every tool at their discretion to accomplish it. Democrats on the other hand love to romanticize everything while clinging to lofty ideals about senate tradition and other unimportant crap.
And right as I sat down to type out a blog about this very subject, Jonathan Chait from TNR published an article addressing the same issue. I highly recommend you read it in its entirety. Don’t worry its not long.