NASCAR fans recently booed first lady Michelle Obama and the vice president’s wife, Jill Biden, after they were introduced as grand marshals for a race at Homestead-Miami Speedway. The women were there to promote a campaign to support U.S military families.

That campaign was the Joining Forces project, which will helps military families gain opportunities for better wellness, education and employment.

A source traveling with the first lady downplayed the incident, telling ABC News there was no discernible booing during the "loud chaotic program with jets flying over and tons of noise." However, the booing was clearly audible in footage from the ESPN live broadcast of the event. In the video above, you can hear it at the 1:35 mark.

The boos for a bi-partisan initiative to help military families reflect just how polarized the country’s electorate is right now.

Eighty percent of NASCAR fans are white, with the majority of them living in South and Midwest, according to NASCAR. Those areas of the country are often Republican strongholds.

The reception may have been different at an event dominated by Latino or black fans.

As Republicans fight to draw in more voters of color, a recent Univision poll found that President Obama is situated to repeat his strong performance with Latino voters in 2012. Other organizations have similarly projected black voter support for Obama’s 2012 campaign.