The demonstrators were key. They were the picture of the story on TV news, the only news that matters. So, how many were there? I don't know; the media were oddly reluctant to say. This AP story says, "the crowd outside the hospice had dwindled to a couple of dozen people by Thursday morning but swelled to more than 100 again as news of Schiavo's death spread." Shall we call it 200?
The Iraq war, on the other hand, is really controversial. The polls show it. But the nationwide series of organized protests which brought about 3000 people made barely a blip in the national media.
The Congressional leadership wasn't saying anything in support of these people. Not even the Democrats -- the opposition party that has convinced itself that it is ungenteel to actually oppose. So, they must not have been worth talking about.
The anti-immigration "Minuteman" nuts doing vigilante border patrols? Outnumbered by the press. But they have support in high places...