Tens of millions of Americans are lining up at the polls amid a raging pandemic on Tuesday to determine whether President Trump will get a second term in office or Democratic nominee Joe Biden will be the nation’s 46th president.

There is tension in the air, as the nation braces for unrest in the streets at a time of deep social and political divisions.

Businesses and storefronts in downtown Washington, D.C., have been boarded up and new steel barriers have been erected outside the White House to defend against potential protests and riots.

Masked voters formed long, socially distanced lines outside of polling places before they even opened this morning in battlegrounds such as Michigan, Wisconsin and Pennsylvania.

There are fears about whether the U.S. Postal Service will be able to handle the late crush of mail ballots, many of which must be received by the end of the day.

A record 100 million people voted before Election Day, as many states pivoted to allow expanded access to early in-person and absentee balloting to make voting safer during the coronavirus pandemic. Campaign operatives estimate another 50 million to 60 million more will cast ballots in person Tuesday.

That’s a big increase from 2016, when 138 million people voted in total, with the strong majority — more than 90 million — voting in-person on Election Day.

“We believe turnout will be significant,” said Biden campaign manager Jen O’Malley Dillon.

The campaigns are on edge in anticipation of reports about disruption and confusion, including manual errors by election officials, partisan court challenges, ballots getting lost in the mail or delivered late, or ballots that are disqualified over technicalities.

There are also fears of election interference from foreign countries after the Director of National Intelligence announced last month that Iran and Russia sent threatening emails to voters after accessing their data.

“Let me be clear, our election infrastructure is resilient, we have no indication that a foreign actor has succeeded in compromising or affecting the actual votes cast in this election,” acting Homeland Security Secretary Chad Wolf said at a Tuesday press conference.

A federal judge on Tuesday ordered the Postal Service to sweep its mail centers and rush to “ensure that no ballots have been held up” at its facilities. Some states, such as Florida, only count ballots received by Election Day, while others, such as North Carolina and Pennsylvania, have a grace period that extends several days after for ballots postmarked by Nov. 3.

As happens every Election Day, there are reports of voters waiting in long lines and some polling place glitches.

In Spalding County, Ga., thousands of provisional ballots were rushed to polling places after election officials caused a malfunction in the machines by loading bad data into them. That resulted in a countywide delay that left many voters stranded in long lines.

But there were also reports of short lines and polling operations running smoothly.

In some instances, the longer lines are due to social distancing and the waits are driven by election officials sterilizing equipment.

The “spoilage rate” for absentee ballots in key states, such as Wisconsin, North Carolina and Florida, is between one-tenth and one-third of 1 percent.

The Biden campaign said it does not see any evidence of systemic failures in the election apparatus at the moment.

“We’re feeling very good about the way the election is running,” said Bob Bauer, a senior adviser to the Biden campaign.

“We’re seeing polling places open and election officials overseeing a process that is affording voters with a fair and inclusive right to vote,” he added.

Both campaigns are talking big about their expected turnout.

White House press secretary Kayleigh McEnany said she believes the president will win in a runaway that includes picking up states Hillary Clinton won in 2016, such as Minnesota and Nevada.

“Our campaign believes that tonight will be a landslide,” she said on "Fox & Friends."

That would be a shocking result, as polls show Biden is the favorite to win nationally and in the key battleground states that will determine the outcome.

Still, Trump has an advantage with the Electoral College, and small variations in turnout could mean the difference between a Biden landslide victory and a narrow Trump victory.

Trump opened the morning by calling into one of his favorite television programs, "Fox & Friends," to say he’s confident he’ll top the 306 Electoral College votes he received in 2016.

The president then made the short trip over to Arlington, Va., to address staffers at his campaign headquarters.

“I just want to say thank you all and get immediately back to work,” Trump said.

The Biden campaign is also feeling good, saying it has been running up the score among early voters in states such as Georgia, North Carolina and Pennsylvania.

O’Malley Dillon says Trump would have to far outpace his 2016 turnout to have a chance to catch Biden.

“We feel well positioned,” O’Malley Dillon said. “All the data we’re looking at underscores how many paths we have and how few paths Trump has.”

Biden visited his hometown of Scranton, Pa., on Tuesday, where he went to church. Biden also visited his childhood home and left his signature on the wall in his old bedroom.

“From this house to the White House with the grace of God,” Biden wrote.

The Democratic nominee will also make a late stop in Philadelphia, before returning home to Wilmington, Del., to watch the results come in.

There could still be a lot of late drama in store after the polls close across the country.

Both campaigns have lawyers on call and ready to fight in the case of a nail-biter election.

And Trump has sought to raise doubts about vote-counting that takes place after Nov. 3, even though it is normal for the official count to drag on for several days past the election.

The results in Pennsylvania aren’t expected until Friday, which is the final day a ballot postmarked by Nov. 3 can be received and counted.

The Biden campaign has plans in place to respond in case Trump declares victory prematurely.

“We’re unfazed by Trump’s desperate attempts to hold on to this election,” said O’Malley Dillion. “The American people will decide. We know some of the results will take a little longer but we’re confident in our path to victory.”

Trump told his staffers he’s not thinking about concession or victory speeches right now. He’s just thinking about winning.

“Losing is never easy, not for me it’s not,” he said.