More than 58 million Americans have already voted

In a key procedural vote Sunday afternoon, the Republicans shut down a Democratic filibuster of the Supreme Court nomination of Judge Amy Coney Barrett.

The vote was 51-48 and Sens. Lisa Murkowski, R-Alaska, and Susan Collins, R-Maine, voted with Democrats. Sen. Kamala Harris, D-Calif., did not vote because she is campaigning in Michigan.

Sunday's vote moves Barrett closer to the final confirmation Monday night, less than two weeks before Election Day.

-ABC News' Trish Turner

Senate Minority Leader Chuck Schumer, in a "Dear Colleague" letter to Democrats Sunday morning urged them to cast their votes on the Senate floor quickly and avoid congregating in the chamber following reports of Senate staff and members of the vice president's team contracting the novel coronavirus.

The Senate convened Sunday afternoon to resume debate on Judge Amy Coney Barrett's nomination to the Supreme Court ahead of Monday's expected final confirmation vote.

Five individuals in Vice President Mike Pence's orbit have tested positive for the coronavirus, including his chief of staff Marc Short and political aide Marty Obst. The vice president and his wife tested negative for the coronavirus Sunday morning.

Pence anticipates continuing his campaign schedule Sunday and said he will be in the Senate Monday for Barrett's confirmation vote.

"While CDC guidelines would dictate contract tracing a quarantining be practiced, our colleagues and the Vice President have indicated that they do not intend to follow such protocols. The Vice President is maintaining his campaign schedule and, inexplicably, intends to preside over the Senate chamber tomorrow evening. Their carelessness with the health and safety of their colleagues and Capitol employees mirrors their carelessness with the health and safety of Americans during this crisis," Schumer wrote. 

"Therefore, considering the Republicans’ refusal follow CDC guidelines regarding quarantining and contact tracing, I would recommend that you not congregate in the Senate chamber today and that you cast your votes quickly and from a safe distance," he continued.

-ABC News' Allison Pecorin

The last day to vote in the 2020 general election is Nov. 3. But ballots may not be counted for several days, if not weeks, after that date, experts said.

Due to an anticipated record amount of mail-in voting this election season, combined with ballot counts that won't start until Election Day in most states, election officials across the country could be overwhelmed in some cases.

Deadlines for receiving mail-in ballots also extend past Nov. 3 in several states, all but making it a given that votes will be recorded in the days or even weeks after the election.

"I buy that we're going to know quite a bit on election night … we could even get an election night call. Still, I would advise caution. If it does come down to the Midwest, we could be waiting for a long time," Nate Silver, editor-in-chief of FiveThirtyEight, said on ABC's "This Week" Sunday,

The issue of mail-in ballot receipt deadlines is also fraught with legal challenges -- some of which are still playing out in court with less than two weeks to go until the general election.

Despite these new complexities, experts are confident voters' ballots will be counted this election season.

Here's a general look at what it takes to tally up the votes of millions of citizens.

Air Force One touched down in New Hampshire a short time ago and was making its way over to the crowd of people waiting for the president's campaign rally.