Wisconsin's northern tier said to be critical in 2012 election

Trip Gabriel of the New York Times reports today on the importance of the rural vote in Wisconsin.  His headline is "In Wisconsin, Real Battleground is Rural."  Here's the story's lede:

The presidential candidates rarely trek this far north, but on election night, experts in the Wisconsin vote said, they would pay close attention to the vast region west and north of Green Bay, viewing it as a telltale of whether the state’s political upheaval since 2010 has undermined President Obama’s bulwark of support.

The rural northern tier may be the most volatile area of the state, where Mr. Obama flipped 19 counties from red to blue in 2008, all of which then shifted back, hard, in a Republican wave two years ago.

Twenty percent of the state's voters live in this "northern tier," an electorate that is "rural, working class, and almost entirely white."  Gabriel's story quotes Paul Maslin, a Democratic pollster in Madison, regarding the region, which he said "nobody ever bothers to go to, where the vote swings the most."    

If Romney wins, it'll be because he made major inroads there. If Obama wins, it'll be because he holds more of the 2008 vote.

PS:  The county-level map for the 2012 election shows that about half of those counties went for Obama, about half for Romney.  It looks like the same counties that went for Obama also went to the Democratic candidate for U.S. Senator, Tammy Baldwin, who also won.