Running mates Joe Biden and Kamala Harris make first appearance together

Democratic presidential candidate and former Vice President Joe Biden and his wife Jill Biden and his running mate Sen. Kamala Harris, D-Calif., and her husband Douglas Emhoff gesture to each other as they practice social distancing during a campaign event at Alexis Dupont High School in Wilmington, Del., Wednesday.

Democratic presidential candidate and former Vice President Joe Biden looks to his running mate Sen. Kamala Harris, D-Calif.

Sen. Kamala Harris, D-Calif., speaks during a campaign event at Alexis Dupont High School in Wilmington, Del., Wednesday.

Democratic presidential candidate and former Vice President Joe Biden and his running mate Sen. Kamala Harris, D-Calif., participate in a campaign event at Alexis Dupont High School in Wilmington, Del., Wednesday.

Democratic presidential candidate and former Vice President Joe Biden, joined by his running mate Sen. Kamala Harris, D-Calif., speaks during a campaign event at Alexis Dupont High School in Wilmington, Del., Wednesday.

Democratic presidential candidate and former Vice President Joe Biden and his running mate Sen. Kamala Harris, D-Calif., arrive for a campaign event at Alexis Dupont High School in Wilmington, Del., Wednesday.

Sen. Kamala Harris, D-Calif., and her husband Douglas Emhoff stand together during a campaign event at Alexis Dupont High School in Wilmington, Del., Wednesday.

Sen. Kamala Harris, D-Calif., speaks after Democratic presidential candidate and former Vice President Joe Biden introduced her as his running mate during a campaign event at Alexis Dupont High School in Wilmington, Del., Wednesday.