Joe Biden: I wasn't surprised Trump got the coronavirus

• "For the last three months, three times a week, I'm on the telephone and on Zoom with some of the leading immunologists in the nation, and they go through everything that's happening," Biden said.
• "So the idea that COVID does not spread in proximity when you don't have a mask on, when you're not socially distancing, when there's large groups of people, when you're inside particularly and even when you're outside, that's not surprising" he added.
• "I would hope that the president having gone through what he went through, and I’m glad he seems to be coming along pretty well, would communicate the right lesson to the American people: Masks matter. These masks, they matter. It matters. It saves lives. It prevents the spread of the disease."

Driving the news: Biden's comments came less than two hours after Trump departed the Walter Reed Medical Center on Monday evening to return to the White House via Marine One following three nights at the hospital for coronavirus treatment.

• Upon reaching the White House, Trump took off his mask and saluted Marine One as photographers encircled him. He then walked into the White House, still maskless.
• Biden later posted a video to Twitter contrasting the pair's stance on wearing masks:

Other key town hall takeaways:

• On last week's presidential debate: Biden said he was "trying to figure out how I could possibly have [Trump] respect the debate, respect the evening, respect the moderator, and get us an opportunity to speak.
• "The one thing that became absolutely clear... he didn't want to answer any questions. He did not want to talk about substance," Biden said.
• "It was all invective. It was all personal ... And I did get very frustrated. I did get frustrated. And I should have said, this is a clownish undertaking, instead of calling him a clown."

"I'll be very honest with you, I think it was embarrassing for the nation to see the president of the United States hectoring like he did and everything was about a personal attack."

• On police reform: "We are going to bring all these interests together, peaceful protesters, police chiefs police officers, police unions, as well as a civil rights groups in the White House and sit down and decide what are the things that need to be done to improve and help police officers," Biden said.

• "I'm the only one who's talked about increasing police budgets ... In addition to that, I'm also proposing that we spend a significant more money on community policing."
• On white supremacy: Biden said that one of the reasons he decided to run for president again was due to the "constant dog whistle" coming from Trump and his supporters.
• Biden pointed to the death of Heather Heyer, who was killed by a neo-Nazi in Charlottesville in 2017: "When a young woman was innocently killed … [Trump] said there are 'very fine people on both sides.' No president has ever said anything remotely like that. So there’s this constant dog whistle and it bothers me a lot."

Editor's note: This article has been updated with new details throughout. It has also been corrected to reflect Heyer was killed in 2017, not 2018.