What If: Can Trump boost turnout among white voters?

Pollsters identify "likely voters" and build a model of what they think the electorate will look like: what percentage of whites, African-Americans, Hispanics; what slice of voters will have college degrees versus a high-school diploma; how many millennials will vote compared with baby boomers.

Exit polls in 2012 showed Obama won just four out of 10 white voters, but still won 332 electoral votes to Romney's 206.

If the electorate stays roughly the same as in 2012, Trump would need to win about two-thirds of the white vote — a significant increase over Mitt Romney's nearly 60 percent and a margin that no candidate has managed since Ronald Reagan's 1984 landslide re-election.

Texas Sen. Ted Cruz, the second place finisher in the GOP nominating fight, argued that the path to Republican victory went through disaffected conservatives who stayed home in 2008 and 2012.