Romney still enjoys the Republicans' traditional advantage among voters who are veterans, but the Obama campaign is confident it can chip away at that.

The president is under 50 percent approval ratings in all the battleground states. So, you could say that President Obama is defying gravity by still being in a dead heat with Mitt Romney. And one of the reasons that he is, is because the changing face of the electorate are giving him a small boost.

Mitt Romney got 59 percent of the white vote in 2012, considered by many to be a high-water mark with this demographic group. Can [Donald] Trump win a higher share of white voters than Romney and get more of them to turn out?

Senate races have tightened along with the presidential race. Watch to see how many Republican Senate candidates outperform Donald Trump - and how many hang on to their seats in states that he loses.

White voters were 72 percent of the electorate in 2012, and their share of the population has shrunk a couple points since then. [Donald] Trump has had trouble winning certain segments of the white vote, such as suburban women and college-educated voters.

In 2012, Hispanics were 10 percent of the electorate, underperforming their share of the voting-age population. Mitt Romney got 21 percent of their vote, and [Donald] Trump has been polling much lower than that.

The Democrats pulled out one of their most powerful surrogates - and no, it wasn't President [Barack] Obama. Beyoncé showed up at a GOTV rally in Cleveland, joining her husband, Jay Z, and Hillary Clinton.