Trump supporters drive their motorcycle March 9 in Miami-Dade County, Fla., an area that is key in winning the Sunshine State. | Getty 16 battlegrounds that will decide the election

There are 200 million registered voters in the United States, and it’s a good bet that more than 120 million of them will cast votes in the presidential race on Tuesday. While every vote counts, not all of them have the same value. In an election that has come down to less than a dozen contested swing states, some places matter a lot more than others.

Here are 16 battlegrounds that will decide the election:


1. Miami-Dade County

If you could know in advance the outcome in just one of the nation’s 3,143 counties, this is probably the one that would provide the most insight into who will win the presidential election. Donald Trump has almost no chance of winning the White House without winning Florida; he has almost no chance of winning Florida if he’s getting blown out in Miami-Dade, the state’s most populous county and home to more than a half-million Hispanic voters (more than half of them Republican).

There’s no shortage of signs that he’s struggling here. Miami-Dade was the only one of the state’s 67 counties he failed to win in the GOP primary; a recent poll of county voters pegged Hillary Clinton’s lead at 30 points. And Trump is underperforming among the traditionally Republican Cuban-American vote, 49 percent to 42 percent.

2. Philadelphia suburbs

Pennsylvania, which looks increasingly crucial to Trump’s chances, comes down to a single number — the Democratic margin produced by Philadelphia, the state’s biggest city. In 2012, that number was 492,000 votes.

To make up that deficit, Trump will have to overperform in the parts of the state where he is strongest -- like western and northeastern Pennsylvania, and in the so-called ‘Republican T’ in the middle of the state. But he’ll also need to be competitive in the four populous collar counties of suburban Philadelphia: Bucks, Chester, Delaware and Montgomery. While he’s got pockets of strength in those places, polls show he’s losing the suburbs by a significant margin — including Chester County , the only one of the four to back Mitt Romney in 2012.

3. Waukesha County, Wis.

Wisconsin’s two most populous counties, Milwaukee and Dane, typically produce big Democratic margins. But the so-called WOW counties outside Milwaukee (Waukesha, Ozaukee and Washington), led by conservative stronghold Waukesha, balance them out. Waukesha is the kind of place that delivers landslide margins to GOP Gov. Scott Walker; if you look hard enough, you’ll see hints of ’60s-era Orange County, California.

While Trump has been gaining traction in places in northern and western Wisconsin, he’s not running nearly well enough in high-turnout Waukesha. He’ll win there, but unless he’s winning at least two-thirds of the vote, his chances of winning Wisconsin are slim.

4. Northern Maine

Maine has never had to divide its electoral votes between candidates since its unusual system of awarding electoral votes by congressional district was adopted in 1972. But Trump’s strength in the more rural of the state’s two congressional districts, the northern-based 2nd District, may change that. And that single vote could be very important under several Electoral College scenarios.

5. Polk County, Iowa

Clinton is going to win Iowa’s most populous county, but the question is by how much. Her campaign will need to run up the score here to offset Trump’s winning margins in rural counties and more conservative areas outside the Des Moines area.

6. Mahoning County, Ohio

This is Jim Traficant country , a white working class area where Trump’s message has taken root. In terms of votes, it pales next to Cleveland’s Cuyahoga County, the state’s biggest source, but if Trump is running well in this longtime Democratic stronghold he’s going to be hard to beat in Ohio. Since polls here close 30 minutes before those in neighboring Pennsylvania, the Mahoning results will also provide an early glimpse into Trump’s likely performance in western Pennsylvania.

7. Wake County, N.C.

There was a time when affluent, well-educated Wake County, home to Raleigh and part of the Research Triangle, was Republican territory in presidential races. But those days appear to be gone — especially with Trump atop the GOP ticket. The Republican nominee’s sweet spot is white, working class voters without college degrees, which is the opposite of who lives in North Carolina’s second-most populous county. Clinton is likely to roll up the score in Democratic Mecklenburg County (Charlotte), the state’s most populous county, so adding a solid winning margin out of Wake County puts her in a decent position to capture the state.

8. Oakland County, Mich.

After Detroit’s Wayne County, Oakland County is the most populous in the state. One of the highest income counties in the nation and a longtime GOP Midwestern stronghold, in recent years the suburban behemoth has begun trending toward Democrats — not even Romney, who grew up here, could win it. At the presidential level, Republicans haven’t won Oakland County since 1992, though George W. Bush twice came very close.

To defeat Clinton in Michigan, Trump will likely need to bring Oakland back into the fold or at least make it competitive. But recent polls have showed he’s losing the educated and affluent county by a big margin, even if he’s well ahead in Macomb County, Oakland’s more working class neighbor.

9. Clark County, Nev.

The question isn’t whether Clinton will win Clark County, the state’s population hub and home to Las Vegas, but by how much. The signs are promising so far for Democrats: Fueled by Latino turnout, Democrats broke the record for early votes cast. For Trump, the path to success includes holding down Clinton’s victory margin in Clark -- where more than two-thirds of the Nevada vote was cast in 2012 — and then winning Reno’s Washoe County, which is considerably smaller but still the second most populous in the state.

10. Northern Virginia

With a 7 p.m. poll closing time, Virginia will be the first battleground state to report results. Ignore the early numbers and wait until around 8:15 p.m., when Northern Virginia’s behemoth, Fairfax County, begins to report its numbers. If Clinton is winning big in populous Fairfax and carrying Loudoun and Prince William counties in the affluent and highly educated NoVa region, she’s on a trajectory to win the state’s 13 electoral votes.

11. Arapahoe and Jefferson counties, Colo.

Suburban Denver’s Arapahoe and Jefferson counties have moved in tandem for the past 10 elections. Both are former GOP strongholds that have voted for Barack Obama twice and have more unaffiliated voters than Republicans or Democrats. Together, the two counties cast 602,000 votes in 2012, which gives Trump a chance to carve into the big Democratic margin Clinton is likely to win in Denver. But each county has a significant Hispanic population, which makes them an uphill challenge for the GOP nominee.

12. Hillsborough and Rockingham counties, N.H.

The two biggest counties in New Hampshire, Hillsborough and Rockingham, cast more votes in the 2012 presidential contest than the state’s other counties combined. Home to Manchester and Nashua, Hillsborough twice voted narrowly for Bush and twice for Obama. Rockingham, however, flipped from Obama in 2008 to Romney.

13. Maricopa County, Ariz.

A late October Arizona Republic/Cronkite News poll gave Clinton a 41 percent to 32 percent advantage over Trump in Phoenix’s Maricopa County, home to roughly two-thirds of Arizona voters. It’s a fairly remarkable result for a county that hasn’t voted Democratic for president since 1948. And without Arizona’s 11 electoral votes, Trump’s chances of victory decrease considerably.

14. Gwinnett County, Ga.

After Atlanta’s Fulton County, Gwinnett is Georgia’s second-most populous county. It has voted exclusively Republican for president since 1980, but the winning percentages have gradually decreased as Gwinnett has evolved into the state’s most racially diverse county. Like Arizona, the loss of this traditionally Republican state from the GOP electoral coalition would all but sink Trump’s chances of winning the White House.

15. Salt Lake County, Utah

In 2012, Romney defeated Obama by 73 percent to 25 percent in Utah — the largest margin of victory in any state. While Utah is among the most conservative states, voters there have such a deep disdain for Trump that it’s not a given that the GOP nominee will win the state, especially with native son Evan McMullin on the ballot as an independent candidate. If Trump falls short on Election Day and is denied the state’s six electoral votes, Salt Lake County, home to roughly 4 in 10 Utahans, will likely play a key role. It’s not as conservative as the rest of the state and was one of just three counties in Utah to vote for Obama in 2008.

16. Omaha, Neb.

Just as Trump could steal an electoral vote out of northern Maine as a result of the way Maine allocates its electoral votes, the same could happen here — but for Clinton. It’s already happened once before, in 2008, when the Obama campaign made a determined effort to win the Omaha-based 2nd District — the least Republican of Nebraska’s three districts. Given Trump’s more limited paths to 270 electoral votes, the loss of even one electoral vote could hurt his chances.