Political conventions

FILE - In this Saturday, June 1, 2019 file photo, Democratic presidential candidate Sen. Kamala Harris, D-Calif., speaks at an SEIU event before the 2019 California Democratic Party State Organizing Convention in San Francisco. Harris is only the second Black woman to serve in the Senate, and in 2020, a prominent contender for the vice-presidential ticket. (AP Photo/Jeff Chiu)

Democratic presidential candidate former Vice President Joe Biden speaks at a campaign event at the William "Hicks" Anderson Community Center in Wilmington, Del., Tuesday, July 28, 2020.(AP Photo/Andrew Harnik)

President Donald Trump steps off Air Force One at Andrews Air Force Base, Md., Friday, July 31, 2020. Trump is returning to Washington after attending events in Florida. (AP Photo/Patrick Semansky)

FILE - In this July 29, 2020, file photo House Speaker Nancy Pelosi of Calif. speaks at a press conference on Capitol Hill in Washington. This election year's battle for control of the House is once again hinging heavily on a fight over suburban voters. Democrats boast an ever-expanding target list that includes a half-dozen Republican seats in Texas plus others outside Atlanta, Cincinnati, Los Angeles and Phoenix. (AP Photo/Andrew Harnik, File)

FILE - In this June 20, 2020, file photo President Donald Trump arrives on stage to speak at a campaign rally at the BOK Center in Tulsa, Okla. Trump is privately reassuring Republicans anxious about his deficits to Democrat Joe Biden, noting there are three months until Election Day and reminding them of the late-breaking events that propelled his 2016 comeback. (AP Photo/Evan Vucci, File)

Democratic presidential candidate former Vice President Joe Biden smiles as he takes a question from a reporter at a campaign event at the William "Hicks" Anderson Community Center in Wilmington, Del., Tuesday, July 28, 2020.(AP Photo/Andrew Harnik)

FILE—In this June 13, 2019 file photo, an Investigator with the Office of the City Commissioners, demonstrates the ExpressVote XL voting machine at the Reading Terminal Market in Philadelphia. As the Nov. 3 2020 presidential vote nears, there are fresh signs that the nation’s electoral system is again under attack from foreign adversaries. Intelligence officials confirmed in recent days that foreign actors are actively seeking to compromise the private communications of “U.S. political campaigns, candidates and other political targets” while working to compromise the nation's election infrastructure. (AP Photo/Matt Rourke, File)

Democratic presidential candidate former Vice President Joe Biden smiles as he takes a question from a reporter at a campaign event at the William "Hicks" Anderson Community Center in Wilmington, Del., Tuesday, July 28, 2020.(AP Photo/Andrew Harnik)

FILE - In this Feb. 9, 2012 file photo, former presidential candidate Herman Cain addresses the Conservative Political Action Conference in Washington. Cain has died after battling the coronavirus. A post on Cain's Twitter account on Thursday, July 30, 2020 announced the death. (AP Photo/J. Scott Applewhite, File)

FILE - In this combination of file photos, former Vice President Joe Biden speaks in Wilmington, Del., on March 12, 2020, left, and President Donald Trump speaks at the White House in Washington on April 5, 2020. The University of Notre Dame has become the second university to withdraw as the host of one of this fall's three scheduled presidential debates amid the coronavirus pandemic. (AP Photo, File)