Bill Enyart, the Democratic nominee for the 12th U.S. House District seat, has an 8-point lead over GOP nominee Jason Plummer, according to a new poll conducted for the Democratic House Majority PAC and the Democratic-leaning Service Employees International Union.

The poll of 400 likely 12th District voters shows Enyart leading Plummer by 49 to 41 percent.

The same poll shows President Barack Obama leading Mitt Romney by 50 to 41, a slight dip from the 11-point margin of victory he had in the district four years ago.

The poll was conducted by the Benenson Strategy Group, which surveyed the voters Sept. 11-13. It has a margin of error of plus or minus nearly 5 percent.

Plummer dismissed the poll results during a conference call Wednesday morning.

"What we have here is, Nancy Pelosi has to save a little face and Bill Enyart and his liberal allies are doing what they can to carry a message that the voters of Southern Illinois just aren't buying," Plummer said. "The only number I'm concerned about is the 10 1/2- percent unemployment rate that this district is facing."

Jason Bresler, Enyart's campaign manager, said he was not surprised the poll shows Enyart leading Plummer "given the reaction we see every day to General Enyart's plan to get the economy moving again in Southern Illinois for middle class workers."

Enyart is "not overconfident," Bresler said, noting that his campaign will "spend the next 48 days highlighting the differences between the general and Jason Plummer."

Plummer had an 11-point lead over Enyart with 23 percent of voters undecided, according to a July poll released Monday by We Ask America.

The automated poll of 1,510 likely 12th District voters found that Plummer, was leading Enyart, 45 percent to 34 percent. The poll has a plus-minus margin of error of 2.5 percent.

Enyart and Plummer are vying with Green Party nominee Paula Bradshaw to replace retiring U.S. Rep. Jerry Costello, D-Belleville, in the Nov. 6 election.

Enyart, 62, of Belleville, is the retired commander of the Illinois National Guard. Plummer, 30, is a Fairview Heights businessman. Bradshaw, 59, is a Carbondale emergency room nurse.

The 12th District comprises a dozen counties that stretch from Alton in Madison County to Cairo in the southern tip of the state.