President Trump, in an echo of his false birtherism claims against President Barack Obama, said questions raised by one of his campaign advisers about the eligibility of Sen. Kamala D. Harris (D-Calif.) to run for vice president were “very serious.”

Harris was born in Oakland, Calif., and is, by the laws of the Constitution, a U.S. citizen. But some birther conspiracy theorists say, wrongly, that her parents’ immigration status at the time of her birth makes her ineligible. Trump’s remarks were a reprise of his past false allegation that Obama was born in Kenya rather than in Hawaii and thus ineligible to serve.

Presumptive Democratic presidential nominee Joe Biden traded attacks with Trump over the coronavirus. Biden called for a minimum nationwide three-month mask mandate to slow the pandemic, which Trump panned as “playing politics.”

This comes one day after the United States reported its highest number of deaths from the coronavirus in a single day since mid-May.

Here are some significant developments: