We Need Checks and Balances

Democrats do not have 60 senate seats. This allows Republicans to filibuster, should they see the need.

Should they see the need?

Politics, as irritating as it is, is a game. The goal of the game is to try to win reelection. It is not to make a difference. While there are some things (game marriage, abortion rights, etc.) that politicians believe in so strongly they cannot vote any other way, the general way that votes work is:

Does voting yes appease my constituents?

If yes, vote yes.
If no, vote no.
If maybe, vote with the party if and only if the measure is likely to pass anyway.

Right now, some 60% of the country approves of the majority of the Democrats' plans. If they filibuster stem cell research, any type of social program that is widely approved, an automotive bailout, healthcare, or anything else that Barack Obama has championed, they are not going to win reelection in 2010 and 2012 as long as Democrats can make sure they take the brunt of the blame.

60 seats would be nice because the Republicans suck on multiple levels, and tend to fight for things that go against the country's interests, only to find a way to blame the Democrats for its failure. But if the Democrats can make their failures public, then it shouldn't matter too much because they will either vote with Barack Obama's plans or secure their own demise.