I grew up near Roscommon. Roscommon County is a swing rural working class county in North Michigan that votes either way due to a mix of union cards and social conservatism. In 2008, Obama got 7082 votes and McCain 6727. In 2012, Romney 6701 and Obama 6198. Buyers remorse for Obama, but Romney did worse than McCain. Bush had 7364 votes.
MANY rural counties are similar, especially in the Midwest. Percentages sometimes mask the actual vote total.
The TOTAL white vote went down in 2012, so Romney's results are less impressive than they appear at first glance.
However, Obama’s share of the white vote went down by 4% in 2012, and Romney's share went up 4%, so it does seem to balance out.
Also, Romney did much better with men than McCain, but McCain did better with women.
Here's the 2008 link:
http://www.ropercenter.uconn.edu/elections/how_groups_voted/voted_08.html
Here's the 2012 link:
http://www.ropercenter.uconn.edu/elections/how_groups_voted/voted_12.html