On a serious note... Missouri is certainly swingable for a good Democratic candidate... certainly if they campaign on economic issues.
For a Democrat to win in MO they need to do well in the St Louis and Kansas City Metro's, the smaller cities in central MO, the old metal mining areas and the Boot Heel.
Certainly not an impossible task
We would be talking about a serious change of tack from the Democrats then that would focus more on populism and most likely lose them some recent gains like New Hampshire, but make them competitive in places like Arkansas, West Virginia, Missouri and Ohio.
I don't think that will happen though. The Democrats are too entrenched as being pro-abortion, pro-gay marriage, etc to make the kind of drastic change required.