Meanwhile, there are some traditional battleground states - like Ohio and Iowa - that are becoming older, whiter and less educated. That's turning them from true battlegrounds into more reliable red states.

People like Ted Cruz, who has tried to position himself as the best second choice for [Donald] Trump supporters, wouldn't condemn him.

Until he announced his immigration policy last week, Obama had the support of most Hispanic voters - but not the enthusiasm they had shown for him in 2008. That may be changing in part because of the decision not to deport young immigrants whose undocumented parents brought them here as children.

Republican voters are coalescing behind [Donald] Trump, but many Republican elected officials still say they can't support him.

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.

The Republican Party, right now, is a conservative populist party.