Trump and Biden locked in a nail-biter as race for the White House comes down to key states

(CNN) President Donald and Joe Biden are slugging out a tight battle for the White House across the country with signs that a momentous election could come down to Arizona, Pennsylvania, Wisconsin and Michigan.

Biden holds the lead in the Electoral College at this stage in the night, 220-213; 270 electoral votes are needed to become president.

Biden was the first candidate to speak to supporters early Wednesday morning, after a night of results didn't deliver a quick winner, saying that "we believe we're on track to win this election."

The former vice president said it was not up to him or Trump to decide the winner of the election and that the votes would be counted.

"Keep the faith guys, we're going to win this," Biden said.

Trump followed Biden's statement with a tweet of his own, claiming to be "up BIG" and promising to make a statement later in the night.

Trump won a close race in Florida, which was one of the states Biden had hoped to peel away from the President's 2016 map and has a narrow edge in North Carolina, which remains too close to call. The former vice president is hoping that Arizona, where he has a 8 percentage point lead with 75% of the ballots counted could be his first victory of the night that turns a red state blue.

Increasingly it appears that the result of the entire election could hinge on whether Biden can restore the Democratic "blue wall" in Michigan, Wisconsin and Pennsylvania, a scenario that could mean the result may not be known on Tuesday night, and could stretch into the coming days as large numbers of mail-in votes are counted.

Biden currently leads the Electoral College at this early stage in the night, but the key battlegrounds that will decide who serves as president for the next four years are still in play.

The night unfolded as the most unorthodox election night in modern memory. At times it appeared like one candidate or the other was heading for an early win in important states. But batches of mail-in and early votes meant the count often dramatically shifted one way or the other.

Polls are now closed across the continental US on a nerve-jangling night that will set the nation's course for the next four years and cast judgment on the most tumultuous presidency of the modern age. Results are flowing in from battlegrounds and it's too early to make a projection in many key states.

CNN projects Biden will win Rhode Island, Minnesota, Virginia, California, Oregon, Washington, Illinois, New Hampshire, New Mexico, Colorado, Connecticut, New Jersey, New York, Vermont, Delaware, Washington, DC, Maryland, Massachusetts and one of Nebraska's five electoral votes. Nebraska awards two electoral votes to its statewide winner and divides three others over its three congressional districts.

CNN projects Trump will also win in Montana, Texas, Iowa, Idaho, Ohio, Mississippi, Wyoming, Missouri, Kansas, Utah, Louisiana, Alabama, South Carolina, North Dakota, South Dakota, Arkansas, Indiana, Oklahoma, Kentucky, West Virginia and Tennessee and four of Nebraska's five electoral votes.

Trump wins two must-have states

Wins for Trump in the Sunshine State and Ohio are crucial to keep open his pathway to win a second term.

Florida Democrats were concerned early in the night about populous southern Miami-Dade County where Biden appeared to be underperforming Clinton's mark in 2016.

The early Biden deficit in Miami-Dade could be a sign of what was apparent in pre-election polls that suggested the President had been making incursions into traditional Democratic support with Black and Latino men. Former President Barack Obama made two trips to Miami-Dade in the closing days of the race to drive up turnout.

Miami-Dade, which Biden is still likely to win, has large concentrations of voters of Cuban and Venezuelan descent who tend to be more conservative than other Latino groups and were targeted by the President with claims that Democrats were akin to socialists.

The President also opened up a solid lead in Ohio after early returns showed Biden in the lead. The Buckeye State was another battleground that Trump's campaign thought he must win in order to earn another four years in Washington. Biden spent time in the state on Monday and was another place that the Democrat had hoped to flip.

Biden does not need to win Florida and Ohio in order to win the presidency, but his campaign had hoped to flip those states after several encouraging polls in the final weeks of the campaign.

Biden performs well in Arizona

Biden appears to have made significant gains in Arizona where demographic changes have accelerated the state's shift from traditional Republican territory to a potential Democratic pick up. The President's unpopularity and the rapid growth of the state -- from its rising Latino population to the influx of retirees from the Midwest and other parts of the country -- has made its politics more unpredictable, even in just the four years since 2016, when Trump beat Hillary Clinton in the state 49% to 45.5%.

Clinton built up Democratic margins in populous Maricopa County, which includes Phoenix and its suburbs -- and the majority of the state's voters -- and Biden appears to be continuing that trend Tuesday night, with turnout looking strong in that key county.

Even within the patchwork of early returns, some trends were emerging that pointed to the fact that is a very different race than 2016. In states like Ohio and parts of Florida, Biden appears to be performing better in the suburbs than Clinton did four years ago. At the same time, the President's team seems to have succeeded in turning out their voters as promised -- in some cases making up for what appeared to be an advantage for Democrats in the early vote count in key swing states.

Results may not be known for days

Millions of ballots were still outstanding in those critical three states of Michigan, Pennsylvania and Wisconsin, many of them vote-by-mail ballots that were cast early and were expected to favor Democrats.

Even Georgia appeared at a standstill as officials in Fulton County, which includes Atlanta and its populous suburbs said they had stopped counting mail-in ballots around 10:30 p.m. ET and that count would resume at 8 a.m. Wednesday. The Fulton County tabulation was initially delayed by a water leak near the room where ballots were being counted but no ballots were damaged.

Election officials in the so-called "Blue Wall" states of the Midwest tried to prepare the public late Tuesday night for the likelihood that a full count would continue through the night, and could stretch well into Wednesday and later this week -- meaning America may not know the winner of the presidential contest for quite some time.

The slow count in those Midwestern states is creating mounting anxiety for Democrats, who had hoped Biden could post some early wins on the board in swing states to prevent President Trump from declaring a premature victory before even crossing the 270 electoral vote threshold that he needs to win.

For weeks now, Trump has hammered the message that voters should know the results on election night -- even though that is rarely the case in America -- while suggesting that a later count could be a sign of voting irregularities, even though there is no evidence to support that and counting has been much more complex this cycle because so many people cast votes by mail in order to stay safe during the pandemic.

Michigan officials are predicting record turnout, and are hoping that ballots counted overnight could give a sense of at least the unofficial result within 24 hours of poll closures, instead of several days as some were initially expecting, but that appeared uncertain.

Michigan Secretary of State Jocelyn Benson told reporters Tuesday night that the state could "potentially see a full result of every tabulation out of Michigan in the next 24 hours," which would be an improvement on the state's original prediction that it would not finish tabulating results until Friday. The state is on track to break turnout records with more than 3 million absentee ballots cast.

"I'm here tonight to ask you all to be patient," Benson said. "No matter how long it takes, no matter what candidates say, we're going to work methodically and meticulously to count every single valid ballot and that, and only that, will determine who wins every race on the ballot in the state of Michigan."

The tipping point state of Pennsylvania may see some of the longest delays, not only because of its very complex ballot with its inner and outer envelopes, but also because election officials were not permitted to start counting the vote-by-mail ballots until Election Day. Late Tuesday night, the Pennsylvania secretary of state urged patience and told result-watchers to expect batches of vote totals to come in in fits and starts throughout the night.

In Wisconsin, some results in the key area of Milwaukee may not be reported until after 5 a.m. on Wednesday, meaning the vote tallies in some of the most critical areas for Biden would not be known until then.