Iowa has a reputation as being a swing state though in the past two presidential cycles, it has leaned reliably Democrat with Barack Obama winning by 10 points in 2008, and 6 points in 2012. However, analysis of the 2014 midterms shows a distinct shift in certain voting blocs that could give Democrats pause in 2016.

Report from FiveThirtyEight:

Republican Sen.-elect Joni Ernst easily won her race in Iowa last Tuesday, beating Democrat Bruce Braley by 8.5 percentage points. Her victory wasn’t shocking, but its size was (to everyone except pollster Ann Selzer, that is). The final FiveThirtyEight projection had Ernst winning by just 1.5 percentage points.

What the heck happened?

Here’s one explanation: White voters in Iowa without a college degree have shifted away from the Democratic Party. And if that shift persists, it could have a big effect on the presidential race in 2016, altering the White House math by eliminating the Democratic edge in the electoral college.

According to the exit polls, however, Braley lost non-college-educated voters of all races by 10 percentage points. His performance among the college-educated matched pre-election polls. But among non-college whites, Braley lost by 14 points.

We can see this in the county-by-county returns. The biggest drop-off from Obama’s 2012 margin to Braley’s 2014 margin was in those counties that had a higher share of whites without a college degree. In those counties, every percentage point of additional non-college-educated voters meant a 0.3 percentage-point drop in Braley’s margin.

The question will be whether this trend continues into 2016 or whether a strong Democratic candidate at the top of the ticket can return the Hawkeye State to the “blue” column. This would be a contrarian view to the demographic shift most political strategists are talking about which is growth in Latino and other minority populations.