Hillary was on the 'pro-war' wing of the Democratic party, and people knew this, thus allowing the natural Republican leanings of the area to come out. There is also that despite being born in Illinois she is identified with New York, and there was a sort of Al Smith/Herb Hoover tension going on, whereas Midwesterner's dislike the Eastern Establishment.
Yes. Obama is the first Midwesterner to win the Democratic nomination since Illinois native Adlai Stevenson was re-nominated by the Democrats in 1956. As Chuck Todd has noted, Obama overperforms expected Democrats margins in every state bordering Illinois except Kentucky, which abuts the most conservative region of Obama's adopted home state.
Voters in ND may be attracted to his brand of Midwestern Democratic politics. For decades they only Democrats they could vote for POTUS were Southerners or East Coasters. North Dakotans may feel more comfortable voting for a pacifist Midwesterner than a bellicose Southerwesterner.
