CHICAGO (CBS) — One issue is the target of the race to replace Jesse Jackson Junior in Congress. Not jobs, not taxes, not the environment, but guns.

The final push is on to get votes in the 2nd congressional district race and candidate endorsements continue to rack up.

North Side Congressman Mike Quigley is the latest to support a candidate. His choice – Democrat Robin Kelly.

One reason? Her support of comprehensive gun legislation.

“I think Robin got an F- from the NRA and anyone who gets an F from the NRA gets an A with me,” said Quigley.

In a statement, Kelly expressed appreciation for Quigley’s backing. Some of her opponents are not only downplaying it, they are trying to use it against her.

“It’s another endorsement from outside of the district,” said Halvorson.

They are also downplaying the push to ban assault weapons and high capacity magazines as a central issue to the race, despite the fact that groups, like New York Mayor Michael Bloomberg’s PAC, are spending millions of dollars in ads targeting Halvorson to keep the issue of guns front and center.

When asked if she thought gun legislation was the main issue, Debbie Halvorson said, “Maybe just like Congressman Quigley, it has been Robin Kelly’s only issue,” said Debbie Halvorson.

Tough words. Gun control is certainly a touchy issue, but one Congressman Quigley believes is top of mind in the Jesse Jackson Junior’s old district.

“I think it’s the issue of the 2nd district and for much of Chicago and the fact that it’s finally heated up,” said Quigley.