Three words:
Blue Dog Democrats.
Yeah, supposedly two years of free legislation... bogged down by power hungry "economic conservative" democrats who stood with the republicans multiple times to block legislation. Despite Obama apparently having a majoraty, every attempt at something truely liberal got blocked in the Senate somehow.
Why? Obama was an idiot who wanted to "change politics" and not bully and strong arm. People complain about lock-step politics, and when someone tries not to use them, they get criticized and punished for it.