Mad,
You said what I've been asking my Muslims freinds around me. It's a good question to ask, "What have Muslims who say extremist don't portrait true Islam, done to stop the terrorist besiding condeming by word and on the newspaper?" I've never had a satisfying answer, it's always like "Koran says this, Koran says that...blah blah blah" Look around the world, they only condem, do nothing, deep down inside they either support or really don't care. It's more upsetting when they target Non-Christian, Non Jews. By that mean, they're saying "we'll kill you ANYWAY, so who do you pick". Hell yea, we'll pick anybody that will not kill us.
A white Christian extremist will be shot by another Christain to let other live including Non Christain. That itself makes them far better choice for us, especially when Muslims are increasing in number.