An underrated point about Missouri in 2008: Obama did really quite well in the suburbs. Only lost Platte by 6.43% in 2008, lost Clay by 0.69%, won St. Louis County by 19.9%, won 41% in Greene County MO, and kept the margin under 10% in St. Charles.
Considering that Gore had
won Clay in '00 (albeit literally by a single vote), this sounds a fair bit less impressive. I wouldn't be surprised if part of it was a function of suburbanization as an ongoing process, but there was nonetheless a contingent that he couldn't quite claw back, alongside or in similar form to the Lead Belt or Bootheel or non-Columbia Little Dixie (where the Democratic vote would soon crater for various reasons, some–like continued deindustrialization in the Lead Belt–more directly related to the administration's policy than others).