For better and worse, democracy in America is changing. The Internet has introduced a new age of mass participation and personal activism in which anyone can be a community organizer, message maker or fund-raiser and mobilize thousands or even millions of people. Though organized money still dominates the game, organized people hold the wild cards.

According to the Pew Center on the Internet & American Life, about 25 million of us are "online political activists" engaged each day in sifting the news, sharing our concerns and...