2016 Election: Vote results, polls and more in battle for the White House

Donald Trump appeared to be closing in on the White House on Tuesday after capturing the key battleground states of Ohio and North Carolina and becoming the apparent winner in Florida.

SEE MORE: In-depth 2016 election coverage

Trump is prevailing in crucial swing states decided so far and holds thin advantages in several others, bringing his tally to 244 electoral votes. Hillary Clinton, who scooped up large electoral vote counts in Democratic strongholds on both coasts, has earned 215 electoral votes.

Razor-thin margins remain in several essential swing states. All eyes are now fixed on Michigan, New Hampshire and Pennsylvania, where Trump and Clinton are running neck-and-neck.

Markets across Asia tumbled and Dow Jones futures plunged more than 800 points amid the uncertainty, potentially reflecting unease about what a Trump administration would mean for the economy.

Here's the current tally, according to NBC News projections:

Clinton wins: California, Colorado, Connecticut, Delaware, Hawaii, Illinois, Maryland, Massachusetts, Nevada, New Mexico, New Jersey, New York, Oregon, Rhode Island, Vermont, Virginia, Washington state and Washington, D.C.

Trump wins: Alabama, Arkansas, Florida (apparent winner), Georgia, Idaho, Indiana, Iowa, Kansas, Kentucky, Louisiana, Montana, Mississippi, Missouri, Nebraska (four of five electoral votes), North Carolina, North Dakota, Ohio, Oklahoma, South Carolina, South Dakota, Tennessee, Texas, Utah, West Virginia and Wyoming.

Too close to call: Arizona, Maine, Michigan, Minnesota, New Hampshire, Pennsylvania and Wisconsin.

Democrats and Republicans are also battling for control of the Senate. Democrats must net four seats to earn the majority. Republicans will keep control of the House of Representatives, NBC News projects.

As millions of Americans cast their ballots Tuesday, early exit polls showed that large majorities of voters had an unfavorable view of both Trump and Clinton.

About six in 10 voters — 61 percent — said they had an unfavorable view of the real estate mogul, while only 37 percent viewed him favorably. A majority of voters — 54 percent — said they had an unfavorable view of the former secretary of state, and another 44 percent viewed her favorably.

The numbers appeared to underscore one of the driving themes of an unusually divisive campaign: Both candidates are astoundingly unpopular.

Heading into Election Day, Clinton held a narrow advantage, leading Trump by 4 points in the last NBC/Wall Street Journal poll taken before Tuesday. If elected, Clinton would become the first woman Commander in Chief.

Trump, the brash political outsider, entered Tuesday with a far more narrow path to 270 electoral votes.

Rush to the polls

Clinton and her husband, former President Bill Clinton, voted at their local polling station in Chappaqua, New York, just after 8 a.m. ET.

"It is the most humbling feeling," the Democratic nominee said. "I'll do the very best I can if I'm fortunate enough to win today."

Trump and his wife, Melania, voted in Manhattan some three hours later.

"We're going to win a lot of states," Trump said in an early-morning interview on FOX News. "Who knows what happens ultimately?"

Meanwhile, some 90 million other Americans were expected to cast ballots, bringing to an end an unusually rancorous and downright wild political drama.

Even before Election Day, some 46 million ballots were cast by early voters and the Democrats were lifted by reports of heavy turnout by Hispanics and women in key states like Nevada and North Carolina.

And despite Trump's repeated claims in recent weeks that the race was "rigged," multiple major city law enforcement agencies told NBC News that Election Day was going smoothly with few problems at the polls, only sporadic reports of voter intimidation, and so far no reports of violence.

Trump has refused to say whether he would concede if he loses, adding another twist to the already dramatic election. His son, Donald Trump Jr., told MSNBC'S "Morning Joe" on Tuesday that his father will concede if the results seem "fair."

The grand finale

The candidates spent the final days of the campaign on a frantic dash through several swing states.

At a massive rally on Philadelphia's Independence Mall on Monday night, Clinton was joined by her husband and daughter, Chelsea. President Barack Obama and first lady Michelle Obama introduced their favored candidate, while rock star Bruce Springsteen energized the crowd with soaring ballads.

"We know enough about my opponent, we know who he is," Clinton said to a crowd of more than 33,000. "The real question for us is what kind of country we want to be."

Trump capped his incendiary campaign with a breakneck tour of battlegrounds, including some Rust Belt states where he has made a late push in recent days, eyeing traditionally Democratic strongholds like Michigan and Wisconsin.

"We have to win," Trump said at his final campaign event in Grand Rapids, Michigan, on Monday night.