MO is polarized to the extreme, I can't imagine her opponent going under 49%. She certainly would have won it in 2008, but not in the shadow of the Obama presidency. I genuinely think she would win AR before MO.
How is AR not just as polarized and hateful of Obama? Missouri has two massive Democratic metro areas unlike Arkansas.
AR is no doubt more even more hateful of Obama. But Clinton has a special appeal there, and the Democratic party has had an advantage in the state up until about 2010. Can't say the same for MO, which has been polarized between the two parties for much longer.