Dubuque County is the sort of county that has made Iowa and the majority of the Midwest lean blue.  The county has not voted Republican since Dwight Eisenhower’s landslide 1956 reelection victory.  Until now.  Donald Trump carried the county by just over 600 or so votes in route to a nine point statewide victory.

This election Dubuque was far from unique.  Rather, it followed a pattern where a majority of the counties that backed Obama in 2008 and 2012 switched their allegiances to Trump all along the upper Mississippi river.  These economically distressed counties share many similarities with their Appalachian cousins but rock-solid red they have not been.  Ever.

The reason is simple.  Obama/Trump voters.  Dubuque County stands as a case study in viewing this phenomenon first-hand.  In 2008 Obama won the county by 21 points with 28,000 votes.  Four years later he won the county by 14 percent with about 28,000 votes. But fast-forward to today and Trump improved on Romney’s margin by over 2,000 vote while Clinton fell over 5,000.  The math is simple to calculate that Trump won over Obama voters.

Dubuque followed a trend, it did not set one.  In Wisconsin, Trump won Kenosha County by an unassuming 250 or so votes.  But, he was the first Republican to do so since Nixon.  In 2012 Obama won the county by 12 percent with 44,000 votes.  Trump won the county with 36,000 votes.  But Clinton under performed Obama by almost 10,000 votes.

The most startling example is in Illinois where Trump flipped every county in Northwest Illinois except Rock Island.  These are not exactly traditional Republican counties as even as they were voting for Trump they were sending Democrats to Congress with north of 60 percent of the vote.  Even in Rock Island Trump improved on Romney’s margins by over 2,000 votes.

Considering Trump’s narrow margins in the Midwest one could easily argue these voters gave him the election.  Though not on the Mississippi River Macomb County is well known for being a home to Reagan Democrats.  In recent years the county had moved left, supporting Obama twice.  But, this go-round the county voted for Trump and gave him a 48,000 vote cushion.  He won the state by a little over 10,000 votes.

In Pennsylvania, Trump carried the state on the backbone of two counties that flipped from Obama to Trump, Luzerne and Erie.  Erie voted for Obama by double-digits in 08 and 12 and Luzerne did as well.  But, this time Trump won Erie narrowly and Luzerne by a stunning 26,000 votes.  These narrow margins took votes Clinton needed and led to her narrow loss.

Right now, Democrats don’t know what to do.  They are at a loss to explain why these voters were drawn to Trump.  Was it the message?  His brand?  His outsider status?  Or was it the Clinton campaign’s ineptitude?  Democrats are not likely to find any quick or easy answers.

As I have written before that the Midwest has been getting redder but nobody foresaw Dubuque County or dozens of counties that voted for Obama flipping to Trump this cycle.  When Joni Ernst was winning Tom Harkin’s open Senate seat in 2014 Dubuque stubbornly stuck to voting for Democrat Bruce Braley.  Still, it echoed a trend, Ernst came close to carrying it.

Considering Trump’s narrow margins Obama/Trump voters mattered more than their weight in paving the way to the White House for Trump.