I think simply waiting for the other side to screw up isn't a successful formula.
Just look at the 2004 elections. The democrats were facing an unpopular president, two wars that weren't going as well as promised, and upper-income tax cuts that weren't helping the middle class, and health care issues getting out of control. It should have been a piece of cake, but the democrats weren't united and lacked a charismatic leader.
Right now the Republicans are up against a popular president and are still perceived as largely to blame for the current economic mess. They need a message and they need a leader. Until they get them, they're dead in the water.
The republicans may have scored a couple cheap political points in the health care debate, but ultimately being against health care insurance reform isn't a particularly good rallying call.