Are 'Tea Parties' Real Politics? Can They Make a Difference?

In the first year of the Obama Administration, the “tea party” movement made almost as much news as the federal stimulus, Wall Street, healthcare and the President himself. But tea-party participants often insist they are “principled conservatives,” not scornful Republicans, even as some Republican leaders try to soak up their energy. Who organizes tea parties?  Who goes to them?  Do they believe in “principles” or the slogans they chant for TV news cameras?  Could they become a coherent “movement” that could be seized by a charismatic candidate, like Sarah Palin?