The longest serving black lawmaker in the Legislature has doubled down on a racially charged attack on Supreme Court Justice Clarence Thomas.  Asked if he stands by his comment that Thomas is an "Uncle Tom," Holmes replied, "Yes, I do."   Pressed for an explanation by Fox News contributor David Webb, Holmes elaborated.  "A black man allow himself to be used to carry the message of a white man, which is against the interests of black people in America, in my opinion that's an Uncle Tom," Holmes said.  "In my opinion, Clarence Thomas is a very prolific Uncle Tom."   The exchange was featured on Fox News Channel's "Hannity."