MSNBC host Chris Matthews, a former Jimmy Carter aide, suggested that the congressional investigation into Attorney General Eric Holder’s handling of Operation Fast and Furious is motivated by racism.

“I don’t want to start too much forest fire here but it is my instinct: is this ethnic?” Matthews asked San Francisco Mayor Willie Brown last night. “It smells like it to me and I think there is a disdain on the part of some Republicans . . . that do talk down to the president and his friends,” Matthews added.

Brown, earlier in the segment, had already accused Issa of “leading a lynch-like mob” against Holder.

Holder made the same accusation in December. “This is a way to get at the president because of the way I can be identified with him,” Holder told the New York Times, “both due to the nature of our relationship and, you know, the fact that we’re both African-American.”

Matthews also took up Holder’s comment about partisan motivations for the accusation. “If he can humiliate this guy, if he can get to him, he’ll be a big star in the Republican caucus,” Matthews said of Issa, before comparing the House investigator — not the president fighting a congressional investigation — to a disgraced president. “He’ll be [Richard] Nixon,” Matthews said.