McCainism And McCarthyism

Which is worse? A reader writes:

Let's clarify how McCainism is different than McCarthyism: McCain is tapping into people's racial fears.  And the thing that hasn't gotten much attention in all of these stories about Obama "being an Arab" and "palling around with terrorists" is that his kind of racism has real impact on people's lives.  Hate crimes against Arabs, South Asians, and anyone with brown skin are perpetrated by the same kind of racism. Distrust of people who look like that affects employment, neighborly relationships, and the kind of hate innocent children have to face at schools. This isn't a senator calling people to testify on Capitol Hill.  This is insidious in a far more subtle, and therefore far more impactful, way.