Al Gore’s Repower America has targeted U.S. Senators Claire McCaskill and Blanche Lincoln, potential fence-sitters on clean-energy legislation in the Senate, with TV ads that aggregate video messages uploaded by constituents. Senators Snowe and Collins are also getting a dose. The commercials come in several flavors, highlighting “rural,” “business,” and “local” voices. It’s a brilliant tactic, a presumably much more effective version of writing a letter to your congressman. As a person who used to answer those letters, I can attest that representatives pay attention when constituents speak up.