Don't set your sights on "massive." As mentioned above, I'll be happy if we can get maybe 200 or so patriots out there. People are all fired up via cyberspace, but it's quite another thing to get 'em out to an event.
We only had about a dozen of us FReepers show up to counterprotest an A.N.S.W.E.R. demonstration in February '03 in Houston.
A dozen of us and about 4,000 of them. And our presence really pissed them off. I'm serious...we threw a quite a damper on their little love fest.
It was wonderful.