Jay Nixon the Democratic governor in 2008 by 58%. In 2012, he won again with 55%.
Clair McCaskill won 55% in 2012 to become Senator.
Democrats also hold the Attorney General and Secretary of State seats.
The state is more likely to flip before Georgia does. Georgia, with Obama at least, had a high floor floor Obama due to black voters but a low ceiling because of the inflexible white vote. Missouri electorate is more fluid and more willing to vote for Democrats.
http://www.surveyusa.com/client/PollReport.aspx?g=56a201bd-db14-4567-bba2-dffea45ee60e A lot has changed between 2008 and now, but just looking in hindsight, when SurveyUSA polled in May of 2008, they found McCain leading Obama by 48-45, while he lost to Clinton 46-48 due to Clinton being stronger with whites and women.