Debate organizers removed the plexiglass barriers initially placed between the candidates’ lecterns after speaking with the government’s top expert on infectious diseases Dr. Anthony Fauci.

Fauci told ABC News Chief White House Correspondent Jonathan Karl that he got a call from Trump’s chief of staff Mark Meadows asking if in his opinion there was a need to have plexiglass between the two candidates.

Meadows then had Fauci talk to a doctor working with the Commission on Presidential Debates, and Fauci explained to the doctor that because the candidates were 12-feet apart, there was no need for plexiglass as droplets wouldn’t reach that far and aerosol isn’t stopped by plexiglass anyway.

Even with the removal of the plexiglass partitions, the coronavirus pandemic is still on display inside the debate hall at Belmont University in Nashville.

All audience members are required to wear masks and will be removed from the event if they refuse, organizers said. The mask requirement comes after several members of the Trump family removed their masks once seated at the first presidential debate in Cleveland.

Singer Kid Rock and professional golfer John Daly, both Trump supporters, were spotted in the audience ahead of the debate’s start without their masks. They put them back on after they were approached by debates staffers.

The FiveThirtyEight politics crew discusses how the last presidential debate might affect the election. Is there still time to shift opinions, or have voters already made up their minds?

In the wake of that canceled second showdown and a chaotic first debate before it, the Commission on Presidential Debates announced earlier this week it would mute candidates’ microphones at certain points Thursday to avoid interruptions and “maintain order.”

Trump and Biden will now have two minutes each of uninterrupted time to speak at the beginning of each 15-minute segment, of which there are six, in the 90-minute debate.

After the first four minutes of each segment, both of their microphones will go live for an “open-discussion portion,” the commission co-chair said. The moderator will not have control of the candidates' mics at any point. Those will instead be controlled by event production staff.

ABC News Chief Congressional Correspondent Mary Bruce said on ABC News Live Prime ahead of the debate, “Just because your microphone is down, doesn't mean that you necessarily will stop talking.”

Trump has attacked the integrity of the debate commission and its chosen moderators in recent weeks, deeming it all "crazy" and the new mic rule "very unfair” -- but sources have told ABC News Chief White House Correspondent Jonathan Karl that some advisers think muting the mics will actually help the president.

Biden, meanwhile, has called the muting of mics "a good idea" and said he’s expecting Trump to fire off personal attacks during their final showdown.

ABC News Chief Anchor George Stephanopoulos said the big question for Biden, who leads in nationwide polls, is whether he can close the deal with voters from Nashville. For Trump, it's how will he adjusts his performance after the "disastrous" first debate more than three weeks ago.

"Even the president's own aides called his blustering performance a self-inflicted wound," Stephanopoulos said.

Pick who wins the race: Forecast if Trump or Biden will win the 2020 presidential election with ABC News' interactive election map.

To win the presidency, candidates have to hit the magic number of 270 electoral votes. The Electoral College comprises a total of 538 members, with each state getting a total number of electoral votes equal to its congressional delegation and three additional electoral votes for District of Columbia.

Biden said if he is elected he would pass Obamacare with a public option, deeming it "Bidencare," and outlining his plan.

"If you qualify for Medicaid and you do not have the wherewithal in your state to get Medicaid, you're automatically enrolled, providing competition for insurance companies," Biden said.

"Secondly, we're going to make sure we reduce the premiums and reduce drug prices by making sure that there's competition that doesn't exist now, by allowing Medicare to negotiate drug prices with the insurance companies," he said.

Biden said private insurance would be protected under his plan.

"Thirdly, the idea that I want to eliminate private insurance -- the reason why I had such a fight for -- with 20 candidates for the nomination, was I support private insurance," Biden said. "Not one single person with private insurance would lose their insurance under my plan, nor did they under Obamacare."

"Lastly, we're going to make sure we're in a situation that we actually protect pre-existing conditions. There's no way he can protect pre-existing conditions. None. Zero," Biden said, as the Trump administration seeks to dismantle the entire Affordable Care Act which currently protects them.

Trump said earlier, "I'd like to terminate Obamacare, come up with a brand-new beautiful health care."