The older I get, the more I see regionalism as a dominant factor in American politics. The punditocracy gives it lip service, but rarely outside of the role of the South in the GOP. America is a nation of distinct regions, and these regions have long had their own unique political styles that remain, even if party affiliation wanders. The Solid South's conversion to the once hated Party of Lincoln is usually the most noted, but equally as momentous is the current destruction of New England's moderate Republican tradition, as evidenced by the recent retirement of Olympia Snow. She is leaving politics and Lincoln Chafee and Jim Jeffords left the Republican Party not because of their own ideological shifts, but because of the conservative orthodoxy of the Dixie-fied GOP.
I hail from the region that seems to the a non-region in the eyes of the rest of the nation: the Midwest. Much ink is spilled each year on the need for Democrats to carve out a niche in the South and West, but the recent success of the Democrats in a region long liable to vote Republican has practically gone without notice. (Illinois, Lincoln's home state and birthplace of Ronald Reagan has gone Democrat in every presidential election from 1992 onward, this after going Republican in all of the presidential elections between 1968 and 1988.) The Midwest not only produced Barack Obama, his support in that region put him over the top against McCain. (Had Ohio voted differently, George W. Bush would have been a one termer.)
In regards to the current presidential primaries, I have heard little to no comment concerning the fact that Rick Santorum appears to have made the Midwest his stronghold. He almost beat Romney in Michigan - Mitt's home state- in a vote so close that I hardly think that Romney could tout it as a victory. Santorum has won Iowa, Minnesota and Missouri (in addition to Colorado in the West), three out of four which voted for Obama in 2008.
It might seem strange at first glance that Santorum, supposedly much more conservative than Romney, would win in states that have been voting for Democrats in recent presidential elections. However, this can be explained by the fact that Midwestern Republicans are different from their counterparts in other regions. Despite the South's reputation as the Bible Belt, social issues matter more for Midwesterners than Southerners on the right. Why? Because the culture of the Midwest accepts public institutions and organized labor as necessary, unlike conservative Southern politicians, who have always advocated for as little government and cheap as labor as possible. Just compare any Southern city to a Midwestern counterpart of similar size, and the latter will invariable have better financed public schools, larger public libraries, and more and better maintained public park space. Certainly Scott Walker has used his power to attack unions, but the level of pushback he has received in Wisconsin is indicative of that state's difference from, say, Texas, where public workers are treated like dogs with little public sympathy.
While it is certainly the case that Midwestern Republicans have put their stock in supply-side Reaganism and such, they are much closer to Democrats on economic issues than their counterparts in other regions. Thus, it is social issues, especially abortion, that define their differences with Democrats. Santorum appeals to these people tremendously (trust me, I've got some in my family), and his seemingly insane pronouncements as of late seem aimed at arousing their enthusiasm at the polls in Ohio on Super Tuesday. However, Santorum appears to have little support outside of the Midwest by comparison. Nobody in the larger news media is saying it, but Santorum is a regional candidate.