The lovable folks at Move America Forward have launched a "You Don't Speak for Me, Cindy" anti-Cindy Sheehan nationwide tour. Of course, Cindy Sheehan has never claimed to speak for all Americans or, really, to speak for anyone but herself. People are quite free to disagree with her, and as far as I know she hasn't suggested otherwise.
So, speak up against the president of the United States and a well-funded right wing group will... speak out against you.
The first set of pro-war rallies, back in 2002, were the same. They weren't pro-war or "pro-American" rallies, they were explicitly anti-American. The "supporters" carried signs expressing hatred for their fellow Americans (Dixie Chicks, Susan Sarandon, etc...) for daring to disagree with them.
They're only happy when they can have a personal enemy, the weaker the better the little cowards.