I think part of it is that many Americans don't understand Islam. I certainly don't enough. But one thing I did 5+ years back was visit Bosnia & Turkey and actually go into some mosques and ask questions. I was lucky because I had that opportunity, not everyone does, and I had some awesome tour guides who explained the basics and let me ask every question I could think of. I came away from that more enlightened and tolerant. That's why I liked Clay's post so much. It shows real people stepping up to the challenge and exhibiting their tolerance. That picture says everything, and I hope more people see it.
"These are Coptic Christians in Cairo’s Tahrir Square, holding hands around Muslims during Friday prayer, to protect them from surprise attack.
We could do this. We could do this here, in the United States, to keep our Muslim citizens safe. All of us, Christians and Jews and atheists, anyone committed to the First Amendment, to the idea that religious freedom is essential to American society, could join hands to protect Muslims living here from rising prejudice."