WASHINGTON — Election Day is upon us. But don’t count on the suspense ending before bedtime, even if you’re a night owl.

A decisive result could take days, as election workers in key battlegrounds tackle stacks of mail-in ballots. Many states put those stacks off-limits until polls opened, so an anxious public will need patience.

That’s a lot to ask, as passions were running high among supporters of President Donald Trump and former Vice President Joe Biden.

Early tallies from Florida and North Carolina could favor Biden, because both states will have already counted mail-in ballots and those tend to favor Democrats. But that could disappear as thorough results come into focus.

For the same reason, Trump could take the early lead in Pennsylvania, where election workers can’t even open the envelopes until polls close, and that could end up being a “red mirage” as mail ballots are counted.

Trump has hinted that he may declare victory on Tuesday night, though the Biden campaign threw cold water on that idea, with campaign manager Jenn O’Malley Dillon insisting Monday that “under no scenario will Donald Trump be declared a victor on election night.”

In his final flurry of rallies, the president pressed his long-standing argument that counting should stop on Election Night — even though it is utterly standard under state election laws for mail ballots to be counted after polls closed.

The big difference this year is the sheer volume. With the COVID-19 pandemic raging, governors and public health authorities urged voters to cast ballots early or by mail, to avoid crowding on Election Day.

Emotions are high, and polls show that roughly three-fourths of Americans expect the outcome to spark violence.

Downtown Washington buildings boarded up windows and scheduled extra security. Dallas businesses were taking similar precautions. Law enforcement was on alert. Gov. Greg Abbott ordered 1,000 National Guard troops to prepare for duty in case of unrest.

“You don’t really need that many people to have substantial violence,” said Filipe Campante, vice dean at the Johns Hopkins University School of Advanced International Studies. “The more relevant question to ponder is that we have gotten to the point where this is even a consideration, and what it speaks to the state of U.S. politics at the moment.”

“The fact that there is, let’s say, a nontrivial probability that we would have scattered episodes of violence in itself is very disturbing,” he said.

Turnout has been staggering. As of Monday, 97.1 million votes have already been cast nationwide, according to the U.S. Elections Project.

That’s 70% of the 2016 vote.

More voters had already voted in two states — Texas and Hawaii — than in the entire 2016 election, even before polls open on Tuesday.

The weather will be spectacular for Texans who vote on Tuesday: sunny and mid-70s across the state.

Strategists on both sides spun the early turnout as a good sign for their candidate.

“You look at your turnout here in Texas, what that tells me is that people will not be intimidated by anyone,” Tom Perez, the national Democratic Party chairman, told reporters in Williamson County. “Texas is going to be razor thin. A number of other battleground states will be razor thin, but I feel like we have a lot of wind at our back.”

Flurry of activity

Both campaigns have armies of lawyers prepared to do battle. Trump’s is led by Texas Attorney General Ken Paxton.

In Houston, a federal judge threw out a GOP effort on Monday to invalidate 127,000 votes cast at drive-through polling sites that Harris County had set up, as a public health measure.

The plaintiffs, including Republican candidates, lawmakers and activists, vowed to appeal to the U.S. Supreme Court, and congressional Democrats have threatened to launch an inquiry into attempted vote suppression.

The all-Republican Texas Supreme Court had already rejected a challenge to the drive-through lanes on Oct. 22, and again on Sunday.

Tarrant County faced a last-minute crisis when scores of ballot counters dropped out. Ballot board members work in pairs, one from each party, to count faulty mail ballots that machines are unable to read. Social distancing isn’t possible and many cited concerns about the coronavirus.

On Monday, the county Election Board met in emergency session and approved 56 new ballot counters.

Dallas County Judge Clay Jenkins urged voters who still want to turn in an absentee ballot to hand-deliver it to the Elections Department at 1520 Round Table, just west of Love Field, or to vote in person at any of the county’s 463 polling stations, rather than relying on the mail.

Records may fall

Through the end of early voting on Friday night, 9,718,484 Texans voted, mostly in person. Under 1 million cast ballots by mail. The record had been 8,969,226, set in 2016.

And that’s not the only record likely to fall.

Trump collected nearly 4.7 million votes in Texas on his way to a 9-point win over Hillary Clinton.

The high mark for a Democrat came two years later, when Beto O’Rourke drew just over 4 million votes as he fell short against Sen. Ted Cruz.

Almost 30 million mail ballots that were requested around the country had not yet been returned by Monday, according to the U.S. Elections Project.

That’s a lot of envelopes to open and validate against registration databases, which is why the top elections officials in the states have counseled patience.

In Dallas County, the Democratic and Republican party chairs issued a joint statement urging patience during the vote count, and neighborly generosity as the dust settles.

“We write in the spirit of bi-partisanship to encourage all of us — the public, government officials, the media, political parties, and candidates — to take a deep breath and stay patient and calm while election officials count all votes, in accordance with the applicable laws,” wrote Democratic chairwoman Carol Donovan and GOP chairman Rodney Anderson. “Remember: a complete and accurate ballot count is more important than a fast ballot count.”

Mail ballots in Texas are valid if they’re postmarked by Election Day and received by the following day. Overseas military voters have even longer.

None of those votes is less valid, or more suspicious, than a ballot cast on the first day of early voting or on Election Day.

Record turnout, the unusually large number of mail-in ballots, and extra safety measures related to the pandemic means that “counting every vote will likely take more time than usual this year. We may not know the winner of the presidential election, and possibly many down-ballot races, on November 3 and, perhaps, for a while after that,” the Dallas party leaders wrote.