Back when Republicans controlled the White House and Congress, all the political energy was on the left -- specifically, the emerging Net Roots movement that dispelled Clintonian centrism from the Democratic party.
These days, with Democrats controlling the White House and Congress, all the political energy is on the right -- specifically, the Tea Party free-market populist movement that opposes big-government spending, taxation, and regulation.
Tea Party enthusiasm has jolted the Republican party from its slumber. When GOP politicians oppose Obama's agenda, they do so because they know the Tea Partiers have their backs. If the Tea Party hadn't started on February 19, 2009, with Rick Santelli's famous rant on CNBC, Republicans would have remained rudderless and disunited throughout Obama's first year in office.
One of the strengths of the Tea Party is that it does not have a leader. The movement is organic, diverse, and in flux. It encompasses all sorts of folks, from disillusioned independents, to Ron Paul supporters, to first-time voters upset at the direction in which America is headed. This poses a political challenge for liberals, since they have found it hard to demonize an entire movement (not for lack of trying!). It is easier to demonize a single person, especially if the public already finds him polarizing.
And while certain Republican politicians are favorites at the Tea Party -- Michele Bachmann, Doug Hoffman, Marco Rubio, Scott Brown -- the activists do not have an icon. They have not rallied behind a single individual.
But that may be about to change.