Labor and immigration leaders joined Vermont Sen. Bernie Sanders outside Philadelphia City Hall for the "For the Workers, Not the Billionaires May Day Rally."
The 2020 Democratic National Convention will take place from August 17-20 with two hours of programming beginning at 9 p.m. ET.
"Nero fiddled while Rome burned," Sanders said. "Trump golfs."
"The path toward victory is virtually impossible," Sanders told supporters as he congratulated Biden.
Joe Biden and Bernie Sanders chose to forego a handshake at the top of the debate, opting instead to bump elbows.
"If I'm elected president, my cabinet--my administration will look like the country," Joe Biden said.