Which non-competitive state in 2012 is most likely to be competitive in 2016?

[Xing]

Apologies if this has been done before. Which state other than Colorado, Florida, Iowa, Nevada, New Hampshire, North Carolina, Ohio, Pennsylvania, Virginia, and Wisconsin is the most likely to be competitive in 2016? Minnesota? Michigan? Georgia? Some other state?

Note that I'm not implying it's probable that Georgia, Michigan, Minnesota, etc. will be competitive, but relatively speaking, which one is the most likely?

[An American Tail: Fubart Goes West]

Arizona could be competitive, but I think it would still be foolish for the Democrats to go after it if there's other targets that are more important.

[IceSpear]

R to D: Missouri, Indiana, Arizona, Georgia
D to R: Minnesota, Michigan, New Mexico

Personally, I'd say Missouri is most likely. Romney's 2012 margin exaggerates the strength of the Republican trend due to the fact that Obama is a poor fit for the state and didn't contest it. If Hillary puts effort into winning it, it could definitely be competitive. Even Obama came within 0.1% in 2008.