We posted the following map at Blawg Review #180, a map taken from the US Census 2000 which shows all the counties in America. Those in light blue color have a plurality of inhabitants claiming German ancestry.

That map (with a couple of Midwestern exceptions) matches two other maps which we previously published on LawPundit showing the year 2008 Presidential Election results (here updated at CNN, November 7) with McCain winning States having LOWER median family income and Obama winning States having HIGHER median family income (note also that those States having a plurality of African-American inhabitants - colored dark purple above - almost all went to McCain and not to Obama.):

CNN MAP of 2008 Presidential Election Results 7 Nov. 2008
(blue=Obama, red= McCain, grey=battleground States not yet 100% decided, but see)
(blue=Obama, red= McCain, grey=battleground States not yet 100% decided, but see)

Regarding this and other maps of American ancestries, see also:
Maps of American ancestries
and
Ancestry : 2000.