I'm still sure Rubio could have put MN in play.
Rubio? If he couldn't remain popular in a Lean R state (Florida), what causes anyone to think that he would do well in Minnesota? Kasich might put Minnesota in play in a 40-state landslide... if the political dynamics remained as they were around a month ago.
Minnesota does not swing much. It may have gone decisively for Obama in 2008, but not by the blowout margins by which he won in a bunch of other states. It was the worst state for Reagan in 1984 and the second-worst for Nixon in 1972 in 49-state blowouts.
The last Republican to win Minnesota decisively was Dwight Eisenhower. But overlay elections of Obama and Eisenhower and you will see some amazing coincidences for two Presidents from the opposite Parties. (Then again, I see similarities of temperament that probably fit some political cultures of some states, and I figure that both Presidents were similarly effective and will be so regarded in the future).