Campaign mugs of clean and dirty pens used for consent forms are seen in the press coronavirus testing center for Democratic U.S. presidential nominee and former Vice President Joe Biden in Wilmington, Delaware, U.S., September 20, 2020. Picture taken September 20, 2020. REUTERS/Mark Makela

A campaign mug of dirty pens used for consent forms is seen in the press coronavirus testing center for Democratic U.S. presidential nominee and former Vice President Joe Biden in Wilmington, Delaware, U.S., September 20, 2020. Picture taken September 20, 2020. REUTERS/Mark Makela

Democratic U.S. presidential nominee and former Vice President Joe Biden speaks about the death of U.S. Supreme Court Associate Justice Ruth Bader Ginsburg shortly after Biden arrived from campaign events in Minnesota at New Castle Airport in New Castle, Delaware, U.S., September 18, 2020. REUTERS/Jonathan Ernst

Democratic U.S. presidential nominee and former Vice President Joe Biden speaks about the death of U.S. Supreme Court Associate Justice Ruth Bader Ginsburg as a U.S. Secret Service agents looks on shortly after Biden arrived from campaign events in Minnesota at New Castle Airport in New Castle, Delaware, U.S., September 18, 2020. REUTERS/Jonathan Ernst

Democratic U.S. presidential nominee and former Vice President Joe Biden speaks about the death of U.S. Supreme Court Associate Justice Ruth Bader Ginsburg as U.S. Secret Service agents look on shortly after Biden arrived from campaign events in Minnesota at New Castle Airport in New Castle, Delaware, U.S., September 18, 2020. REUTERS/Jonathan Ernst

Democratic U.S. presidential nominee and former Vice President Joe Biden speaks about the death of U.S. Supreme Court Associate Justice Ruth Bader Ginsburg shortly after Biden arrived from campaign events in Minnesota at New Castle Airport in New Castle, Delaware, U.S., September 18, 2020. REUTERS/Jonathan Ernst

Democratic U.S. presidential nominee and former Vice President Joe Biden speaks about the death of U.S. Supreme Court Associate Justice Ruth Bader Ginsburg shortly after Biden arrived from campaign events in Minnesota at New Castle Airport in New Castle, Delaware, U.S., September 18, 2020. REUTERS/Jonathan Ernst

Democratic U.S. presidential nominee and former Vice President Joe Biden speaks about the death of U.S. Supreme Court Associate Justice Ruth Bader Ginsburg shortly after Biden arrived from campaign events in Minnesota at New Castle Airport in New Castle, Delaware, U.S., September 18, 2020. REUTERS/Jonathan Ernst

Democratic U.S. presidential nominee and former Vice President Joe Biden speaks about the death of U.S. Supreme Court Associate Justice Ruth Bader Ginsburg shortly after Biden arrived from campaign events in Minnesota at New Castle Airport in New Castle, Delaware, U.S., September 18, 2020. REUTERS/Jonathan Ernst

Democratic U.S. presidential nominee and former Vice President Joe Biden speaks about the death of U.S. Supreme Court Associate Justice Ruth Bader Ginsburg shortly after Biden arrived from campaign events in Minnesota at New Castle Airport in New Castle, Delaware, U.S., September 18, 2020. REUTERS/Jonathan Ernst

Democratic U.S. presidential nominee and former Vice President Joe Biden speaks about the death of U.S. Supreme Court Associate Justice Ruth Bader Ginsburg shortly after Biden arrived from campaign events in Minnesota at New Castle Airport in New Castle, Delaware, U.S., September 18, 2020. REUTERS/Jonathan Ernst

Democratic U.S. presidential nominee and former Vice President Joe Biden speaks about the death of U.S. Supreme Court Associate Justice Ruth Bader Ginsburg as U.S. Secret Service agents look on shortly after Biden arrived from campaign events in Minnesota at New Castle Airport in New Castle, Delaware, U.S., September 18, 2020. REUTERS/Jonathan Ernst

Democratic U.S. presidential nominee and former Vice President Joe Biden speaks about the death of U.S. Supreme Court Associate Justice Ruth Bader Ginsburg shortly after arriving from campaign events in Minnesota at New Castle Airport in New Castle, Delaware, U.S., September 18, 2020. REUTERS/Jonathan Ernst

Democratic U.S. presidential nominee and former Vice President Joe Biden gestures as he boards his campaign plane to depart Minnesota and return to Delaware after presidential campaign stops in Duluth, Minnesota, U.S., September 18, 2020. REUTERS/Jonathan Ernst

Democratic U.S. presidential nominee and former Vice President Joe Biden boards his campaign plane to depart Minnesota and return to Delaware after presidential campaign stops in Duluth, Minnesota, U.S., September 18, 2020. REUTERS/Jonathan Ernst

Democratic U.S. presidential nominee and former Vice President Joe Biden is surrounded by reporters and microphones as he talks at the Duluth Airport prior to departure after presidential campaign stops in Duluth, Minnesota, U.S., September 18, 2020. REUTERS/Jonathan Ernst

Democratic U.S. presidential nominee and former Vice President Joe Biden is surrounded by microphones as he talks to reporters at the Duluth Airport prior to departure after presidential campaign stops in Duluth, Minnesota, U.S., September 18, 2020. REUTERS/Jonathan Ernst

Democratic U.S. presidential nominee and former Vice President Joe Biden talks to reporters at the Duluth Airport prior to departure after presidential campaign stops in Duluth, Minnesota, U.S., September 18, 2020. REUTERS/Jonathan Ernst

Democratic U.S. presidential nominee and former Vice President Joe Biden talks to reporters at the Duluth Airport prior to departure after presidential campaign stops in Duluth, Minnesota, U.S., September 18, 2020. REUTERS/Jonathan Ernst

Democratic U.S. presidential nominee and former Vice President Joe Biden gets elbow bump greetings from local supporters who his campaign said had voted for him for president during the first day of early 2020 general election voting in Minnesota earlier in the day, during a campaign stop in Duluth, Minnesota, U.S., September 18, 2020. REUTERS/Jonathan Ernst

Democratic U.S. presidential nominee and former Vice President Joe Biden is surrounded by reporters and microphones on the Duluth Airport tarmac before departing after campaign events in Duluth, Minnesota, U.S., September 18, 2020. REUTERS/Jonathan Ernst

Democratic U.S. presidential nominee and former Vice President Joe Biden talks to reporters on the Duluth Airport tarmac before departing after campaign events in Duluth, Minnesota, U.S., September 18, 2020. REUTERS/Jonathan Ernst

Democratic U.S. presidential nominee and former Vice President Joe Biden talks to reporters on the Duluth Airport tarmac before departing after campaign events in Duluth, Minnesota, U.S., September 18, 2020. REUTERS/Jonathan Ernst

Democratic U.S. presidential nominee and former Vice President Joe Biden talks to reporters on the Duluth Airport tarmac before departing after campaign events in Duluth, Minnesota, U.S., September 18, 2020. REUTERS/Jonathan Ernst

Democratic U.S. presidential nominee and former Vice President Joe Biden talks to reporters on the Duluth Airport tarmac before departing after campaign events in Duluth, Minnesota, U.S., September 18, 2020. REUTERS/Jonathan Ernst

Democratic U.S. presidential nominee and former Vice President Joe Biden talks to reporters on the Duluth Airport tarmac before departing after campaign events in Duluth, Minnesota, U.S., September 18, 2020. REUTERS/Jonathan Ernst

Democratic U.S. presidential nominee and former Vice President Joe Biden speaks with Minnesota Governor Tim Walz, Duluth Mayor Emily Larson and others as he sits down with supporters outside a coffee shop during an unscheduled campaign stop in Duluth, Minnesota, U.S., September 18, 2020. REUTERS/Jonathan Ernst

Democratic U.S. presidential nominee and former Vice President Joe Biden speaks to union carpenters and reporters during a campaign event at the Jerry Alander Carpenter Training Center in Hermantown, a suburb of Duluth, Minnesota, U.S., September 18, 2020. REUTERS/Jonathan Ernst

Democratic U.S. presidential nominee and former Vice President Joe Biden speaks to union carpenters and reporters during a campaign event at the Jerry Alander Carpenter Training Center in Hermantown, a suburb of Duluth, Minnesota, U.S., September 18, 2020. REUTERS/Jonathan Ernst

A supporter of U.S. President Donald Trump yells at Democratic U.S. presidential nominee and former Vice President Joe Biden as Biden sits talking with supporters outside a coffee shop during an unscheduled campaign stop in Duluth, Minnesota, U.S., September 18, 2020. REUTERS/Jonathan Ernst

Democratic U.S. presidential nominee and former Vice President Joe Biden adjusts his face mask as he talks with Duluth Mayor Emily Larson outside a coffee shop during an unscheduled campaign stop in Duluth, Minnesota, U.S., September 18, 2020. REUTERS/Jonathan Ernst

Democratic U.S. presidential nominee and former Vice President Joe Biden talks with firefighters during an unscheduled stop at a Duluth fire station while campaigning for president in Duluth, Minnesota, U.S., September 18, 2020. REUTERS/Jonathan Ernst

Democratic U.S. presidential nominee and former Vice President Joe Biden brings box of Great Harvest Baking Company cookies to firefighters during an unscheduled stop at a Duluth fire station while campaigning for president in Duluth, Minnesota, U.S., September 18, 2020. REUTERS/Jonathan Ernst

Democratic U.S. presidential nominee and former Vice President Joe Biden talks with firefighters during an unscheduled stop at a Duluth fire station while campaigning for president in Duluth, Minnesota, U.S., September 18, 2020. REUTERS/Jonathan Ernst

Democratic U.S. presidential nominee and former Vice President Joe Biden arrives to speak to union carpenters during a campaign event at the Jerry Alander Carpenter Training Center in Hermantown, a suburb of Duluth, Minnesota, U.S., September 18, 2020. REUTERS/Jonathan Ernst

Democratic U.S. presidential nominee and former Vice President Joe Biden talks with a mother and her two young children during an unscheduled campaign stop on the street after a campaign event in Duluth, Minnesota, U.S., September 18, 2020. REUTERS/Jonathan Ernst

Democratic U.S. presidential nominee and former Vice President Joe Biden arrives to speak to union carpenters during a campaign event at the Jerry Alander Carpenter Training Center in Hermantown, a suburb of Duluth, Minnesota, U.S., September 18, 2020. REUTERS/Jonathan Ernst

Democratic U.S. presidential nominee and former Vice President Joe Biden sits down and talks with supporters outside a Duluth coffee shop during an unscheduled campaign stop in Duluth, Minnesota, U.S., September 18, 2020. REUTERS/Jonathan Ernst

Democratic U.S. presidential nominee and former Vice President Joe Biden gets an elbow bump greeting from Minnesota Governor Tim Walz as he arrives for an unscheduled outdoor campaign stop after an event in Duluth, Minnesota, U.S., September 18, 2020. REUTERS/Jonathan Ernst

Democratic U.S. presidential nominee and former Vice President Joe Biden is applauded by supporters on the street during an unscheduled campaign stop after an event in Duluth, Minnesota, U.S., September 18, 2020. REUTERS/Jonathan Ernst

Democratic U.S. presidential nominee and former Vice President Joe Biden talks with two young boys holding Biden Harris campaign stickers during an unscheduled walk on the street while campaigning in Duluth, Minnesota, U.S., September 18, 2020. REUTERS/Jonathan Ernst

Democratic U.S. presidential nominee and former Vice President Joe Biden talks with two young boys holding Biden Harris campaign stickers during an unscheduled walk on the street while campaigning in Duluth, Minnesota, U.S., September 18, 2020. REUTERS/Jonathan Ernst

Democratic U.S. presidential nominee and former Vice President Joe Biden sits down with local supporters and Minnesota Governor Tim Walz at an outdoor coffee shop during an unscheduled stop while campaigning in Duluth, Minnesota, U.S., September 18, 2020. REUTERS/Jonathan Ernst

A union carpenter and a U.S. Secret Service agent watch and listen as Democratic U.S. presidential nominee and former Vice President Joe Biden speaks during a campaign event at the Jerry Alander Carpenter Training Center in Hermantown, a suburb of Duluth, Minnesota, U.S., September 18, 2020. REUTERS/Jonathan Ernst

Democratic U.S. presidential nominee and former Vice President Joe Biden pauses as he speaks to union carpenters, union officials and reporters during a campaign event at the Jerry Alander Carpenter Training Center in Hermantown, a suburb of Duluth, Minnesota, U.S., September 18, 2020. REUTERS/Jonathan Ernst

Democratic U.S. presidential nominee and former Vice President Joe Biden puts his protective face mask worn because of the coronavirus disease (COVID-19) pandemic back on after speaking to union carpenters, union officials and reporters during a campaign event at the Jerry Alander Carpenter Training Center in Hermantown, a suburb of Duluth, Minnesota, U.S., September 18, 2020. REUTERS/Jonathan Ernst

A crowd of supporters of Democratic U.S. presidential nominee and former Vice President Joe Biden hold Biden Harris campaign signs as they watch Biden's motorcade drive past after a Biden campaign event in Duluth, Minnesota, U.S., September 18, 2020. REUTERS/Jonathan Ernst

Supporters of Democratic U.S. presidential nominee and former Vice President Joe Biden hold Biden Harris campaign signs and wave a Biden for President flag as they watch Biden's motorcade drive past after a Biden campaign event in Duluth, Minnesota, U.S., September 18, 2020. REUTERS/Jonathan Ernst

A supporter of Democratic U.S. presidential nominee and former Vice President Joe Biden watches Biden's motorcade drive past while holding "Care for People More Than Money," "Black Lives Matter" and "Minnesotans for Biden Harris" signs after a Biden campaign event in Duluth, Minnesota, U.S., September 18, 2020. REUTERS/Jonathan Ernst

Democratic U.S. presidential nominee and former Vice President Joe Biden elbow bumps a union official after speaking to union carpenters and reporters during a campaign event at the Jerry Alander Carpenter Training Center in Hermantown, a suburb of Duluth, Minnesota, U.S., September 18, 2020. REUTERS/Jonathan Ernst

Democratic U.S. presidential nominee and former Vice President Joe Biden speaks to union carpenters, union officials and reporters sitting socially distanced because of the coronavirus disease (COVID-19) pandemic during a campaign event at the Jerry Alander Carpenter Training Center in Hermantown, a suburb of Duluth, Minnesota, U.S., September 18, 2020. REUTERS/Jonathan Ernst

Democratic U.S. presidential nominee and former Vice President Joe Biden smiles as he speaks to union carpenters, union officials and reporters during a campaign event at the Jerry Alander Carpenter Training Center in Hermantown, a suburb of Duluth, Minnesota, U.S., September 18, 2020. REUTERS/Jonathan Ernst

Democratic U.S. presidential nominee and former Vice President Joe Biden speaks to union carpenters, union officials and reporters during a campaign event at the Jerry Alander Carpenter Training Center in Hermantown, a suburb of Duluth, Minnesota, U.S., September 18, 2020. REUTERS/Jonathan Ernst

A sign requiring personal protective masks and a circle indicating social distancing because of the coronavirus disease (COVID-19) pandemic are seen on the floor as Democratic U.S. presidential nominee and former Vice President Joe Biden speaks to union carpenters, union officials and reporters during a campaign event at the Jerry Alander Carpenter Training Center in Hermantown, a suburb of Duluth, Minnesota, U.S., September 18, 2020. REUTERS/Jonathan Ernst

Democratic U.S. presidential nominee and former Vice President Joe Biden speaks to union carpenters, union officials and reporters about the Trump administration's policies during a campaign event at the Jerry Alander Carpenter Training Center in Hermantown, a suburb of Duluth, Minnesota, U.S., September 18, 2020. REUTERS/Jonathan Ernst

Democratic U.S. presidential nominee and former Vice President Joe Biden speaks to union carpenters, union officials and reporters about the Trump adminsitration's policies during a campaign event at the Jerry Alander Carpenter Training Center in Hermantown, a suburb of Duluth, Minnesota, U.S., September 18, 2020. REUTERS/Jonathan Ernst

Democratic U.S. presidential nominee and former Vice President Joe Biden pauses as he speaks to union carpenters, union officials and reporters during a campaign event at the Jerry Alander Carpenter Training Center in Hermantown, a suburb of Duluth, Minnesota, U.S., September 18, 2020. REUTERS/Jonathan Ernst

Democratic U.S. presidential nominee and former Vice President Joe Biden speaks to union carpenters, union officials and reporters during a campaign event at the Jerry Alander Carpenter Training Center in Hermantown, a suburb of Duluth, Minnesota, U.S., September 18, 2020. REUTERS/Jonathan Ernst

Democratic U.S. presidential nominee and former Vice President Joe Biden speaks to union carpenters, union officials and reporters during a campaign event at the Jerry Alander Carpenter Training Center in Hermantown, a suburb of Duluth, Minnesota, U.S., September 18, 2020. REUTERS/Jonathan Ernst

Democratic U.S. presidential nominee and former Vice President Joe Biden speaks to union carpenters during a campaign event at the Jerry Alander Carpenter Training Center in Hermantown, a suburb of Duluth, Minnesota, U.S., September 18, 2020. REUTERS/Jonathan Ernst