One year before their likely matchup in a key 2010 Senate race, Missouri Secretary of State Robin Carnahan (D) and Rep. Roy Blunt (R) are locked in a dead heat, according to a new survey conducted by the Democratic firm Public Policy Polling.Carnahan garnered 43 percent in the poll of 736 voters, while Blunt got 42 percent. The poll was conducted Nov. 13-15 and had a 3.6-point margin of error. Carnahan is running even with Blunt even though the poll showed more respondents view the Congressman unfavorably (38 percent) than favorably (30 percent). The poll showed Carnahan with favorable/unfavorable ratings of 40 percent and 36 percent.Blunt’s campaign is helped by President Barack Obama’s mediocre approval rating in the state, which the president narrowly lost last year to Sen. John McCain (R-Ariz.). Obama had an approval rating of 43 percent and a disapproval rating of 52 percent, and 55 percent disapprove of his plans to overhaul the health care system.Blunt is in his seventh term representing the southwestern 7th district and is a former member of the GOP leadership team, though his long government service is not a major asset. When respondents were asked if Blunt’s 13 years in Congress made him “part of the problem or part of the solution when it comes to huge deficits and too much government spending,— 65 percent said that made Blunt part of the problem.Carnahan and Blunt have sparred for months as if they were already general election opponents in the race to succeed retiring Sen. Kit Bond (R). Democrats say Blunt is too close to lobbyists and Republicans say Carnahan has ducked discussion of major issues and votes.Blunt is being challenged in the Republican primary next August by state Sen. Chuck Purgason, who is running a lightly funded campaign. The new poll showed Blunt ahead of Purgason 53 percent to 16 percent.