A towering barrier against protesters surrounds the White House as Americans deliver a final verdict on their next commander-in-chief.
Inside the "anti-scale" fence, similar to one that went up during anti-racism protests earlier this summer, Donald Trump intends to ride out tonight's electoral storm.
On the other side, activists who fear Trump will declare a premature election win are expected to take to the streets as the election results come in.
After weeks of record-setting early voting, polling stations in Washington's northern Virginia suburbs were largely quiet, while long lines plagued latecomers in battleground states like Florida and Pennsylvania.
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Janice Sebring, a Trump supporter in a "Make America Great Again" hat, was handing out Republican sample ballots outside the community centre in Vienna, a community 30 kilometres west of D.C.
Sebring says Republicans are less inclined to vote early and prefer to show up on election day to cast their ballots in person.
Asked her feelings about the night's likely outcome, Sebring paused briefly as a hint of uncertainty crossed her face.
"I'm an optimist," she said.
"I think that my candidate is going to do well. Whether he'll do well in Virginia is another question, but I think he's going to do better than expected."
Sebring said like many across the U.S., she's also bracing for unrest in the wake of the results.
"I'm very concerned that, regardless of how the election turns out, that there will be a lot of violence in the cities from Antifa and (Black Lives Matter). I think they're just primed to do something."
Indeed, businesses that line the D.C. streets around the White House had largely locked their doors and boarded up storefronts for fear of a long night of protests.
Polls suggest Democratic nominee Joe Biden has a substantial leg up on his Republican rival, but Trump is not without a path to the 270 electoral votes needed to declare victory.
Both candidates are expected to make speeches tonight, but no one is expecting a concession.
With countless mail-in ballots still to be counted, a conclusive result is not expected to materialize right away. But media reports suggest Trump is poised to seize on an early lead as an excuse to declare himself the winner.
Voters are also deciding who will have control of the Senate: Democrats need a net gain of three seats to wrestle it back from the Republicans if Biden wins. They are widely expected to retain control of the House of Representatives.
