By BRIAN A. HOWEY, in Indianapolis

1. Notre Dame bows out of presidential debate

Here are your Tuesday properly socially-distanced outdoor power lunch talking points: I attended the Bill Clinton/Bush41 debate at Michigan State University in 1992 and it was a career highlight. The media scrum near the filing center was great fun. So I was greatly anticipating the first 2020 presidential debate at Notre Dame, which would have been the first in Indiana history.

But this pandemic is spoiling everything. Notre Dame President John Jenkins announced Monday that health precautions and coronavirus constraints led to the debate cancellation, following a similar decision by the University of Michigan. Jenkins made the decision after consulting with Dr. Mark Fox, St. Joseph County’s deputy health officer, and members of the board of trustees. “The inevitable reduction in student attendance in the debate hall, volunteer opportunities and ancillary educational events undermined the primary benefit of hosting — to provide our students with a meaningful opportunity to engage in the American political process,” Rev. Jenkins wrote.

2. America's baseball experiment teeters

After just one weekend of Major League Baseball, 14 Miami Marlins have tested positive for COVID in Philadelphia, scrambling the first revival of professional sports. MLB Commissioner Rob Manfred: "I don't put this in the nightmare category. It's not a positive thing, but I don't see it as a nightmare. That's why we have the expanded rosters. That's why we have the pool of additional players." Philadelphia Inquirer: Marlins players, aware of the team outbreak, decided via group text to play on Sunday against the Phillies, circumventing MLB's 113-page safety manual. It's hard to imagine how a normal office is supposed to reopen when MLB players — subject to much more stringent oversight than most workers — can seemingly ignore their league's safety policies. Axios: This is a bad sign for baseball. But it's also a bad sign for just about everything in our daily lives — showing that something approaching normal can't simply be willed into existence.

3. Dr. Carroll on testing

Indiana University's Dr. Aaron E. Carroll writes in a New York Times op-ed: "We made a mistake at first with how we talked about masks. We’re making the same mistake now with tests." The professor of pediatrics at IU's School of Medicine and the Regenstrief Institute explains, "There are models showing that if masks are about 60% efficient, fewer than three-quarters of people would need to wear them to keep a disease like Covid-19 in check. Today we’re in danger of making the same mistake with tests. Many schools and colleges are hoping to test students often to keep any transmission in check, and frequent testing of big groups of people may be the only way to stop this virus, short of a vaccine." Dr. Carroll explains, "Tests that collect samples this way may be less precise. But they could be collected really quickly, in large groups, with minimal supplies. They could even be collected by individuals themselves in their homes. We could do tons of them. We could also pool tests. In many areas of the United States where Covid-19 is not prevalent, you could mix samples and run them together. If a pooled sample tests negative, you can assume no one person in the pool is infected and move on. If the pool is positive, you have to run the component samples from each person."

4. Trump/Pence reelect relies on vaccine

President Trump and Vice President Pence are hoping their "October surprise" includes a COVID vaccine. The two visited vaccine research companies in North Carolina and Florida Monday. “I heard very positive things,” Trump in North Carolina, saying of a timetable, "by the end of the year we think we’re in very good shape to be doing that.” Pence said in Florida, “It’s a historic day, a day when we begin in earnest to work on a vaccine,” Pence said. “We want to ensure we move at a safe and effective pace. I want to assure the people of Florida and people all across this country that we will cut no corners in the development of this or any vaccine." CNN: The first Phase 3 clinical trial of a coronavirus vaccine in the United States began Monday. The investigational vaccine was developed by the biotechnology company Moderna and the National Institute of Allergy and Infectious Diseases.

5. Battleground state polling

Morning Consult released polling results from 12 battleground states, calling President Trump's reelection race against Democrat Joe Biden an "increasingly daunting" challenge: Arizona Biden up 49-42% (2016 margin Trump +3.5); Colorado Biden up 52-39% (Clinton +4.9); Florida Biden up 49-46% (Trump +12); Georgia Biden up 47-46% (Trump +5.1); Michigan Biden up 52-42% (Trump +0.3%); Minnesota Biden up 47-44% (Clinton +1.5%); North Carolina tie 47% (Trump +3.6%); OhioTrump up 48-45% (Trump +8.1%); Pennsylvania Biden up 50-42% (Trump +0.7); Texas Biden up 47-45% (Trump +9%); Virginia Biden up 52-41% (Clinton +5.4); and Wisconsin Biden up 50-43% (Trump +0.7%).

Thanks for reading, folks. It's The Atomic!