Midwest states Romney won
Indiana
Missouri
North Dakota
South Dakota
Nebraska
Kansas
States Obama won
Ohio
Michigan
Wisconsin
Illinois
Minnesota
Iowa
Indiana, North Dakota, South Dakota, Nebraska, and Kansas have carried the same in all presidential elections since 1920 with the exception of Indiana having become a Democratic pickup for Barack Obama in 2008. They are a case example of why the Democrats ought to realize that they're capable of carrying more than around 30 states and enjoy a good landslide. After all, the former domain of a prevailing electoral map for the Democrats used to include Arkansas, Louisiana, Kentucky, Tennessee, and West Virginia. And Barack Obama cumulatively did a lot better in the Indiana group than the Arkansas one.
As for Missouri: I would look to it possibly being a companion state to Indiana. Out of the bellwether category, yes, but not permanently unwinnable. The Democrats won over Indiana, in 2008, with less than 60 percent carriage of available states. By comparison to Woodrow Wilson (1912), Franklin Roosevelt (1932, 1936), and Lyndon Johnson (1964), those winning Democrats carried Indiana as part of electoral maps where 80 percent-plus of available states ended up in their columns. So something remarkable happened in 2008. And in both 2008 and 2012, Missouri and Indiana had margin less than 1.50 percent in their spreads.