DENVER — Issues of racism and sexism have broken open in the Illinois delegation to the Democratic National Convention in Denver today, hampering efforts of Barack Obama’s home team to show a united front to the country tonight.

It began when Illinois Senate President Emil Jones, a veteran African-American lawmaker from Chicago and Obama’s political mentor in Springfield, allegedly called another black Illinois delegate an “Uncle Tom’’ late Sunday because she was supporting Hillary Clinton instead of Obama. Jones has denied making the remark (first reported in the Chicago Sun-Times), and was telling reporters on Monday that the other delegate, Delmarie Cobb of Chicago, had misunderstood him.

But by the morning breakfast meeting of the state’s delegation, the racial spat had morphed in a gender one. Several Illinois Clinton supporters – already outcasts among the state’s overwhelmingly pro-Obama delegation – argued that the incident was another example of racial politics trumping gender politics during and after the contentious party primaries.

“African-American women in particular had to choose between supporting an African-American or supporting a woman,’’ said Bonnie Grabenhofer of Illinois NOW, who isn’t a delegate but is in Denver this week accompanying a friend who is a Clinton delegate. “(Jones) essentially said that it wasn’t a legitimate choice that she made.’’

At the breakfast delegate meeting at the downtown Marriott, state party leaders struggled to gloss over the rift on a day that will feature several top Illinois officials on the convention stage. Illinois Attorney General Lisa Madigan, Treasurer Alexi Giannoulias and Comptroller Dan Hynes all are slated to speak early this evening about their thoughts on Obama.

“Walk the streets of Denver knowing that Barack Obama is one of ours,’’ Hynes told Illinois delegates at the breakfast meeting, one of several speakers who appealed for unity. Chicago Mayor Richard Daley’s appeal from the podium was more blunt. “We don’t want to hear any dissent,” he told the gathering.

In this video, Grabenhofer explains some women’s continued anger at the convention: