One thing the republicans seem to have is party discipline. It seems that whatever they want to get passed be it tax cuts, legislation that corporations like, judges, it seems that republicans band together really well. There may be a few dissenters here and there but all in all, they have good party discipline and are able to push an agenda.
Why is this? Why can't democrats have the same kind of party discipline? I suspect that it's because they aren't as tough on their own members as the republicans are. The republican leadership isn't above punishing its own whether it be committee assignments, pork, or cutting off campaign funding and even threatening to back primary challengers.
Should the democrats play a little rougher? Should they bully their own if they have to? In a way it seems wrong to do this but on the other hand, the republicans have been able to push whatever agenda they so desire with strong party discipline on their side. They only need a handful of democrats and they don't even have to worry about a filibuster. Democrats just don't seem to have any party discipline whatsoever. The balance of power in Washington is tipped so far to the right as it is. Party discipline on the democratic side is needed to hold republicans in check.