Gerlach has been campaigning on the issue, too, telling U.S. News earlier this year that the prescription drug plan was one of his biggest accomplishments as a legislator. "It is an important program for seniors and something I am very proud of," he says.

Turnout among elderly voters will be key for both candidates in November.

Meanwhile, a new poll shows Murphy and Gerlach in a statistical dead heat, with the challenger holding a slight edge. A late July survey by Garin-Hart-Yang found that Murphy leads Gerlach 42 percent to41 percent. The narrowing gap is significant in light of three other factors: Gerlach's sinking job approval rating, President Bush's poor job approval ratings in the district, and the fact that Gerlach defeated Murphy by only a 51 to 49 percent margin in the 2004 contest. Also, political pundit Larry Sabato has listed the sixth district as a possible pick up for Democrats, the only Republican-held seat he has listed as a probable Democratic pickup.

--Alex Kingsbury