WASHINGTON (AP) — The likely Donald Trump-Hillary Clinton race won't be a contest over who can win the most votes nationwide. U.S. presidential contests are essentially simultaneous, winner-take-all state elections to choose electors. Whoever wins a majority of electoral votes — that's 270 votes — wins the presidency.
A state's share of electoral votes is roughly related to its population. So it would seem logical for candidates to focus their attention on the most populous states, which offer the most electoral votes. But that's not the case. Many of the biggest states are reliably Democratic or Republican, so campaigns don't waste much time on them. Instead, they focus on states less predictably Democratic or Republican, the so-called battleground states.
The Associated Press explains what battleground states are and why they are important.
THE RED, THE BLUE AND THE PURPLE
American political junkies look at the map of the United States and see a patchwork of mostly red and blue. Red states are the ones that usually vote Republican, such as Texas and Wyoming. Blue states are reliably Democratic, such as New York and Vermont.
But there are also spots of purple. About a dozen of the 50 states are not consistently red or blue. Those are the battleground states. The biggest are Florida and Ohio. Those are the states that often effectively decide elections.
The map gives a clear advantage to Clinton, the presumed Democratic nominee. If she captures all of the states that have voted solidly Democratic in the last six presidential elections, she would start out with 242 electoral votes. Trump, the presumptive nominee, would start with just 102. That number is higher, though, if states that voted Republican in the last four elections are included.
Even with Clinton's advantage, she can't reach the 270 votes without winning some battleground states. Or at least one. If she keeps the 242 electoral votes and wins Florida too, she wins the presidency.
ALL VOTES ARE NOT EQUAL
California has 55 electoral votes. New Hampshire has four. Yet presidential campaigns may try harder to woo voters in New Hampshire than in California.
That's because New Hampshire is a battleground state. California isn't.
Trump says he can win California, but the odds are against him. The state has voted overwhelmingly for Democrats in the last six presidential elections and there's little indication that will change. New Hampshire leans Democratic, but the votes there have been closer and a Clinton win isn't assured.
There's little incentive for either Clinton or Trump to spend precious time and money on states where the outcome appears to be a foregone conclusion. New Hampshire is another matter.
That doesn't mean states like California are ignored altogether: Candidates do swing by for fund-raising.
BLUE IS THE NEW PURPLE
The political map is in a perpetual state of flux, especially because of population shifts.
California, which had Ronald Reagan and Arnold Schwarzenegger as Republican governors, was once a battleground state. An influx of Democratic-leaning Hispanic voters now makes it very hard for Republicans to compete in presidential elections.
North Carolina and Virginia had been solidly Republican. Now they are swing states. West Virginia used to be solidly Democratic. Now it leans Republican.
Candidates often talk about remaking the political map. This year is no different. Trump says he can win over blue-collar voters in northern industrial states like Pennsylvania and Wisconsin, which have been reliably Democratic. Clinton supporters suggest she could win in Republican strongholds like Georgia with the help of an increasingly engaged African-American population, or even conservative Utah, where the large Mormon population has shown disdain for Trump.
Sometimes it's worthwhile for campaigns to target a rival's state even if a win is unlikely. Campaigns try to force rivals to defend the rival's turf while their own candidate focuses on battleground states — the ones that really swing elections.