PBS ultimately concludes it's because republicans view Eric Holder as a liberal. In reality, it's about Eric Holder being the nation's first black attorney general. Same old republican crap. I don't think republicans think that they're being racist. They just feel that Holder is the kind of attorney general that's going to favor black people over white people. That's the real issue for republicans. They're afraid.
It's tough for the media to report on racism without appearing biased, but on this humble blog, I can call it as I see it.