Reps. Danny Davis (D-Ill.) and Bobby Rush (D-Ill.) endorsed former Cook County Administrator Robin Kelly (D) for the House seat formerly held by Rep. Jesse Jackson Jr. (D-Ill.), a potentially big boost to her campaign in the crowded field.

Kelly has been campaigning hard on the issue of gun control, as both of her main opponents — former Rep. Debbie Halvorson (D-Ill.) and Illinois state Sen. Toi Hutchinson (D) — have previously scored well in the National Rifle Assocation's (NRA) ratings. Davis and Rush are Chicago's two African-American congressmen, and the district is heavily African-American, while Halvorson is the only white candidate in the race.

"Our communities are facing an epidemic of gun violence, and we need more members of Congress who can be trusted to fight for common sense gun control measures. Robin Kelly is a woman of integrity and conviction, and President Obama, Congressman Davis and I need her as our partner in ending gun violence," Rush said in his endorsement.

"Robin Kelly has the kind of pragmatism that you need to get results in Washington, while never compromising her beliefs like many do.  If we are going to stop the NRA in their tracks, and make our communities safe again, Robin Kelly is the right woman for the job," Davis said.

Gun control legislation has emerged as the key issue in the race. Halvorson has had ads run against her by New York City Mayor Michael Bloomberg's (I) super-PAC over her opposition to an assault-weapons ban. The issue is particularly salient in the district, which stretches from South Side Chicago into the southern Chicago suburbs, a region where gang violence is a big problem.

While Halvorson had the highest name identification there are signs that the race is turning into a two-way competition between Kelly and Hutchinson, as Halvorson has raised almost no money for the campaign. Kelly recently released a poll that had her leapfrogging Halvorson into first place at 26 percent to 22 for Halvorson and 20 for Hutchinson. Halvorson had actually lost ground from the previous poll, while Kelly and Hutchinson had both gained.

The primary vote will occur in late February.