Get ready for another Missouri barnburner.

Secretary of State Robin Carnahan maintains a one-point lead over Rep. Roy Blunt (R-Mo.) in the state's open Senate race, according to a new Public Policy Polling (D) survey. That is virtually unchanged from other polling on the race, which has been sparse but has shown Carnahan with a modest lead.

But despite her negligible lead, Carnahan has significantly better favorability numbers: 40 percent favorable and 36 percent unfavorable, compared to 30 and 38 percent, respectively, for Blunt. Voters also say, 65 percent to 35 percent, that Blunt has been part of the problem when it comes to government spending too much.

PPP spokesman Tom Jensen attributes the discrepancy to President Obama's poor numbers in the state. He is viewed favorably by 43 percent of voters, versus 52 percent unfavorably. And his healthcare plan tests poorly, with just 34 percent of voters supporting it and 55 percent opposing it. These are similar to the numbers we saw in a Quinnipiac poll of Ohio last week.

PPP also finds Blunt having little trouble with primary opponent and state Sen. Chuck Purgason. Blunt leads the little-known challenger 53-16, cracking the all-important 50 percent barrier.