President Joe Biden on Thursday mistakenly referred to Vice President Kamala Harris as “Vice President Trump” in the opening question of his highly-anticipated solo press conference in Washington. “Look, I wouldn’t have picked Vice President Trump to be vice president [if] I think she’s not qualified to be president,” Biden said, confusing his second-in-command with his November election opponent, former President Donald Trump. The president misspoke and appeared to lose his train of thought several times as he fielded reporters’ questions. In another blunder, Biden wrongly referred to his chief of staff as “my commander in chief” before catching his...