"World News Tonight" anchor David Muir asked ABC News Chief White House Correspondent Jonathan Karl, who watched the dueling town halls, if the separate appearances moved the needle for people who were undecided.

Karl said that there are so few Americans who are undecided at this point.

"This is such a strange campaign. We have heard very little from either of these two men on about what they would actually do over the next four years," Karl said

Karl noted that after dodging questions on his stance on expanding the Supreme Court, Biden answered Thursday night after being pushed by Stephanopoulos.

"We have what appears to be a commitment that after the Amy Coney Barrett vote, he will tell the American people. He said voters have the right to know where he stands," Karl said.

During Trump's town hall, the president didn't answer a question from a voter on his plan for rising health care costs, something Karl said the president had four years to come up with.

"It was abundantly clear that he has absolutely no plan. This is something he's had four years, nearly four years in office, to come up with," Karl said.

"He basically said that what he has done is he's done away with the individual mandate with Obamacare, and then talked a little more about Obamacare is not a good thing, and we need something better, but absolutely nothing about what he'd actually do on health care," he added.

BIDEN'S CLAIM: "My deal is a crucial framework, but not the New Green Deal."

FACT CHECK: In addition to misstating the name of the Green New Deal, Biden was incorrect in how he laid out his view of the plan compared to how it is stated on his own campaign website.

"Biden believes the Green New Deal is a crucial framework for meeting the climate challenges we face," his website reads.

While Biden has said he does not support major aspects of the Green New Deal, his own plan calls for moving the nation's power system to net-zero emissions by 2035, a more ambitious timeline than his original climate plan laid out, which has been praised by progressive activists.

The Green New Deal was a resolution that laid out a broad framework for climate action but would not have changed any policies if it had passed.”

In one major distinction from that framework, Biden said he does not think it would be possible to completely eliminate fossil fuels by 2030, saying the country will need to be able to transition to more investments in renewable energy while improving sources that can release greenhouse gas emissions like natural gas.-ABC News' John Verhovek and Stephanie Ebbs

ABC News senior congressional correspondent Mary Bruce said viewers saw something that they haven't seen very often due to the pandemic: Biden interacting directly with voters.

"His campaign feels he shines in these moments, that he does best when he is able to speak directly with voters," she said.

"There was a lot of deep diving that he was doing into his policy proposals going forward. This was a night largely about Joe Biden and, actually surprising, not a lot about his opponent," she added.

BIDEN'S CLAIM: "I do not propose banning fracking. I think you have to make sure that
fracking is, in fact, not admitting methane or polluting the well or dealing with what can be small earthquakes and how they're drilling. So it has to be managed very, very well, No. 1. No. 2, what we have to do is the future rests in renewable energy."

FACT CHECK: Biden said he does not support a ban on fracking, the shorthand for the process of extracting natural gas, but he does support limiting its environmental impact, blocking its use on public lands and putting more focus on renewable energy.

The debate around fracking has focused on whether a candidate would "ban" the entire industry, but a president would only have the power to stop issuing new leases for oil and gas activity on public land, not activity on private property.

Biden has said that he doesn't want to add new fracking on public lands. He has said he wants to move away from fracking and focus on more renewable energy sources to eventually get net-zero emissions, including preventing the release of the methane from natural gas activity.

He has also argued that a transition to clean energy is necessary to keep people employed and that it won't be possible to immediately eliminate all fossil fuels, including natural gas.

Biden's environmental plan calls for an end to fossil fuel subsidies and for a massive investment in clean energy, including training fossil fuel workers for clean energy jobs.

-ABC News' Stephanie Ebbs and Averi Harper

BIDEN'S CLAIM: "All the way back in the beginning of February, I argued that we should be keeping people in China. And we had set up, in our administration, a pandemic office within the White House."

FACT CHECK: Biden's comments about what his administration would have done differently at the beginning of the pandemic were lacking some context.

What Biden appeared to be referencing was the United States having Centers for Disease Control and Prevention staff based in China in order to monitor the spread of the virus. Reuters reported earlier this year that the Trump administration had cut the number of staff in China by more than two-thirds, mostly over the previous two years in the agency's Beijing office.

In a Democratic presidential primary debate in February, Biden referred to funding cuts for public health agencies. "What I would do immediately is restore the funding," he said then. "I would be on the phone with China and making it clear, we are going to need to be in your country."

His answer at the town hall Thursday night did not provide that full context, though, which made it sound like he could have been referring to whether he supported putting restrictions on travelers coming from China to the United States, a step President Donald Trump took at the beginning of February.

It was not until the beginning of April that Biden's campaign confirmed in a statement to CNN that he supported Trump's decision to bar some travel from China, because the move was supported by scientists and medical experts.

-ABC News' John Verhovek