Racial infighting among Democrats, which marred the presidential primaries, has flared up again at the party’s convention in Denver, where a black Hillary Clinton delegate is accusing a black Barack Obama delegate of calling her an “Uncle Tom.”

Delmarie Cobb of Chicago said that Illinois Senate President Emil Jones, whom Obama called his “political godfather,” hurled the racially charged insult against her late Saturday for speaking out in support of Clinton. Although Democrats at the convention are trying to project an image of unity, there is lingering bitterness between the Clinton and Obama camps, in part because each side accused the other of playing the race card during the primaries.

On Monday, Illinois’ National Organization for Women President Bonnie Grabenhofer reportedly called on Jones to resign immediately from the Illinois state Senate for using the racial slur.

“That was a pretty horrible comment,” Grabenhofer, also a Clinton delegate, told The Sun-Times.

Cobb said Jones called her “Uncle Tom” in front of a group of Chicago aldermen in a hotel lobby after the two began a playful conversation that turned edgy as Cobb accused Jones of gloating over Obama’s victory. Jones then insinuated that Clintons played “gutter politics,” according to Cobb, who ended the conversation by announcing it was “time for me to go.”