A new poll shows Democrat Robin Carnahan with slim leads over three Republicans in an early hypothetical matchup of probable U.S. Senate candidates.

The survey, by Public Policy Polling, showed Carnahan, the secretary of state, leading Republican Roy Blunt, the congressman from southwest Missouri, by 45-44 percent.

She led former Sen. Jim Talent by 47-43 percent. And Carnahan topped former state treasurer Sarah Steelman by 47-36 percent.

Carnahan also gets the best marks for favorability, with 45 percent of voters having a positive opinion of her and 36 percent viewing her unfavorably.

Talent’s numbers are similar at 45/39. Blunt has the only negative numbers of the quartet of candidates at 40/43, an indication, perhaps, that his son's recent tenure as governor may be hurting him.

Steelman is not as well known as the others, with 35 percent of respondents saying they have no opinion of her either way.

"If she runs, Robin Carnahan has to be considered the frontrunner for Missouri’s open Senate seat in 2010," said Dean Debnam, President of Public Policy Polling. "At the

same time it’s also clear she won’t run away with it. Missouri has had some of the most competitive elections in the country over the last decade, and this one could well join that list of closely contested races."

PPP surveyed 867 Missouri voters on January 10 and 11. The survey’s margin of error is plus or minus 3.3 percent.

More here.