Hillary Clinton's inability to attract millennials is causing her to lose ground in swing states -- and even safe Democratic states like Illinois.

A Loras College Public Opinion Survey released on Monday showed Donald Trump beat Clinton among millennials in Obama's home state. While the former first lady led the billionaire by 14 percent overall, she lost young voters by two points.

According to the poll, Clinton received 47 percent of the vote in Illinois, Trump took 33 percent, Gary Johnson got 8 percent, and the Green Party's Jill Stein received 3 percent.

Among millennials though, Clinton lagged behind with just 31 percent (her lowest percentage among any age group). Trump came in first among young voters, winning 38 percent of the vote. Johnson captured 8 percent of the millennial vote, and Stein won 5 percent. More than one-in-five said they were undecided.

Ironically, young voters were the worst age group for Clinton, and the only group Trump won.

In 2012, President Obama won 68 percent of young voters in his home state. Clinton is on track to lose more than half of that number and while it may not be enough to flip Illinois, it will be enough to paint a sea of red in other swing states.