I know not every conservative thinks Muslims are terrorists -- the thrust of my response was that modern conservatism attracts and encourages people with this mindset. You'll occasionally get people who are typically left-leaning but oddly embrace hardcore xenophobia (I know at least one person on this forum like that), but conservatism's tendency toward the "unfamiliar things are scary" attitude is a logical fit.
And it's kind of interesting how you claim that xenophobia on the right is "not even close" to being a uniform belief, but yet say that it's a "common theme" for people on the left to think that black people can't be racist. Really? No. I suspect there are some people who think that way, but every argument I've seen centers around black people simply being less prone to racism by having experienced its effects first-hand. And there's little doubt that they're more often the victims of racism than the perpetrators, especially in the US.
There's a simple reality that non-whites (ie non-dominant groups) are treated according to the image of their group, which is why "here's some minorities doing uppity things" threads were so popular here before there was a price to be paid. Notice the underlying mentality of that behavior: to elevated their own group's social status by relegate others to some underclass. These people know what's going on, and choose to proceed accordingly, so thus should be judged based on their choices.
