TRUMP'S CLAIM: Can you imagine where they say you have to have your ballot in by Nov. 10? Nov. 10. That means that's seven days after the election, in theory, should have been announced. We have major states with that -- all run by Democrats, all run by Democrats. It's a fraud. It's a rigged election.

FACT CHECK: It is true that mail ballots arriving after Nov. 3 will be counted in several states, but these ballots are not fraudulent.

For these mail ballots to be counted, they must be postmarked on or before Election Day, and in some states, they must be postmarked by the day before the election.

In a normal election year, 19 states accept ballots that arrive after the election, as long as they are properly postmarked and arrive within a state-specific timeline, between three and 14 days post-election, according to the National Conference of State Legislatures. These states are not "all run by Democrats" either. Alaska, Iowa, Maryland, Mississippi and Ohio -- all states with Republican governors currently -- have postmark-by deadlines on the books, even when there isn't a pandemic causing widespread changes to voting.

More states will have postmark-by deadlines for the November election, due to both court rulings and changes implemented by state officials.

In Wisconsin on Tuesday, for example, a federal appeals court upheld a lower court's ruling, which ordered county election officials to accept ballots received up to six days post-election as long as those ballots were postmarked on or before Nov. 3. Other battleground states where court rulings have extended the deadline for mail ballots to arrive include Michigan, Pennsylvania and Georgia, but the extension is being challenged in all three states.

In Kentucky, Democratic Gov. Andy Beshear and Republican Secretary of State Michael Adams reached a bipartisan agreement in mid-August to accept ballots returned by mail through Nov. 6, as long as those ballots are postmarked on or before Nov. 3.

-- ABC News' Quinn Scanlan

Following the debate, Biden campaign officials said they had their best fundraising hour of the entire campaign between 10 p.m. and 11 p.m. ET and that the former vice president’s callout during the debate to Iwillvote.com led to the most concurrent users in the website’s history.

TRUMP'S CLAIM: "It's China's fault, it should have never happened. They stopped it from going in. But it was China's fault. By my doing it early -- in fact, Dr. Fauci said, 'President Trump saved thousands of lives.' Many of your Democrat governors said, 'President Trump did a phenomenal job.'"

FACT CHECK: Trump is overstating his early actions in containing the virus by suggesting his travel restrictions from China were critical.

While Dr. Anthony Fauci has confirmed that those restrictions were important, Trump is omitting a major miscalculation he made early on in the pandemic -- not restricting travel from Europe.

"The president's decision to essentially have a major blocking of travel from China, that already had an effect of not seeding the way, in Europe," Fauci told ABC News Chief Anchor George Stephanopoulos on "This Week" in March. "What we're doing now with the other travel restrictions -- so you block infections from coming in," Fauci continued, adding that containment and mitigation efforts were implemented to keep us away from that worst-case scenario."

Up to 75% of the coronavirus specimens circulating in the New York City area in early March were genetically similar to strains seen in Europe and other areas of North America, according to a Centers for Disease Control and Prevention study published in July.

Although Fauci has said that the president's travel restrictions did save lives, he has also stated on numerous occasions that if mitigation efforts such as social distancing and mask wearing were implemented earlier, then many lives could have been saved.

"I mean, obviously, you could logically say that if you had a process that was ongoing and you started mitigation earlier, you could have saved lives. ... If we had right from the very beginning shut everything down, it may have been a little bit different," Fauci said during an interview on CNN in April.

-ABC News' Arielle Mitropoulos

ABC News Chief Anchor George Stephanopoulos called Tuesday's debate the worst he has ever seen in his life.

"I have to speak personally here, as somebody who's watched presidential debates for 40 years, as somebody who's moderated presidential debates, as someone who's prepared candidates for presidential debates, and someone who's covered presidential debates, that was the worst presidential debate I have ever seen in my life -- a lot more heat than light over some 90 minutes," he said.

ABC News Chief White House Correspondent Jonathan Karl said, "It looked as if both men lost this debate" but added that it was Trump who had more to lose.

"In that sense the real loser is Donald Trump," Karl added. "Donald Trump was the one that needed to change the dynamic of this race."

ABC News' Senior Congressional Correspondent Mary Bruce reported that the Biden's campaign is "feeling very good right now," following the debate, saying they believe every time Biden "went around the president" and spoke directly to the viewers "they were winning."