Election security updates: Officials brace for Election Day under cloud of threats

In a win for the Republican National Committee, the Georgia Supreme Court on Monday ruled that thousands of voters whose mail-in ballots were delayed will not have extra time to send them back.

The ruling from the court reversed a lower judge's ruling that had granted 3,000 voters an extension of the mail-in-ballot deadline, after Cobb County election officials admitted they missed the deadline to ship them out.

The deadline for mail-in ballots to be received in Georgia is Election Day -- but the lower judge had given those voters an extension for them to be postmarked by election day and received by Nov. 8, the same deadline for overseas ballots.

The RNC had appealed the ruling, saying it was a violation of the election code and that voters still had other ways they could vote, including in person.

The Georgia Supreme Court ordered the Cobb board to "keep separate" the absentee ballots of those voters that are received after the deadline on Election Day but before Nov. 8 "in a secure, safe, and sealed container separate from other voted ballots."

Cobb County had previously been ordered to ship out all of the delayed ballots by Nov. 1 with express shipping and overnight return envelopes.

The court also ordered the board to notify the voters by email, text or public announcement of the change.

-ABC News' Olivia Rubin

At a rally in Reading, Pennsylvania, on Monday, Trump called on residents to turn out and vote tomorrow.

"If we win Pennsylvania, we win the whole ball of wax," he said. "It's over. It's over."

"We're just one day away. Oh, we've been waiting for this. I've been waiting four years for this," he said.

Washington, D.C., officials say they have no credible threats to the city, however, they will be fully activating police and have received support from Virginia and Maryland law enforcement agencies.

"I feel very strong about the district's preparation," Mayor Muriel Bowser said Monday. "I feel very sad that this is the state of things to be honest with you, but the way that I deal with anxiety is to work and to make sure that we are as prepared as we can be, and that people, all people, win or lose, do the right thing."

D.C. police will have increased patrols in key areas downtown and around the White House, Police Chief Pam Smith told reporters Monday.

"[The] proactive presence is a preventive measure, and while there is no credible threat to the District of Columbia, we want residents and visitors alike to feel sure that MPD is here prepared and dedicated to keep communities safe across all seven districts.," Smith said.

The mayor said before Jan. 6 and the inauguration she expects to make a National Guard request for additional assistance, but no request will be made for election week.

-ABC News' Beatrice Peterson

Philadelphia Judge Angelo Foglietta said he plans to issue a decision "shortly" after a nearly six-hour hearing over Elon Musk's America PAC's million-dollar giveaway, as Philadelphia District Attorney Larry Krasner is seeking an emergency injunction to stop the sweepstakes.

During closing arguments, a lawyer for Krasner called Musk's giveaway "one of the great scams of the last 50 years" by deceiving more than a million swing state voters to sign a petition in the hopes of winning a million dollars.

"There is nothing random about that process,” the lawyer, John Summers, said. "This was a profound, devastating and widespread deception."

Summers argued that Musk attempted to "influence the election" by encouraging hundreds of thousands of voters to sign a petition while preselecting the winners based on their "suitability" to serve as spokespeople for the political action committee. Summers argued that even if the lottery was not random, it's still illegal under Pennsylvania law.

"They essentially advertised this as a lottery. It’s not a defense that what we said it was isn't true," Summers said.

Andy Taylor, a lawyer for Musk’s America PAC, argued that the DA’s case falls apart after today's revelation that the alleged lottery awarded preselected winners.

"It's an opportunity to earn. It's not a chance to win," Taylor said, emphasizing the winners' roles as spokespeople for the PAC.

Taylor emphasized that the case centers on a petition in support of the First and Second amendments, arguing that shutting down the giveaway would infringe on free speech.

"You are going to smother in the crib the rights of millions of Pennsylvanians from exercising constitutional magnitude free speech," Taylor said.

Speaking outside court, Krasner’s attorney declined to comment on the specifics of the case, simply acknowledging, "It's in the hands of the judge."

-ABC News' Peter Charalambous