PHILADELPHIA (KABC) --Signs of a divided party were apparent at the Democratic National Convention on Monday, as Bernie Sanders supporters loudly booed whenever Hillary Clinton's name was mentioned.
The Vermont senator's supporters are angry over recently leaked emails that show Democratic Party leaders favoring Clinton before the primaries were concluded. At a Florida delegation breakfast, Democratic party chair Debbie Wasserman Schultz was heckled by Sanders' loyalists. It was her first time speaking publicly since announcing her resignation over the leaked emails.
Clinton supporters hope the convention will eventually become a show of party unity.
"This is democracy at its best," said delegate Wendy Greuel, the former Los Angeles city controller and a Clinton supporter. "Sometimes it's messy and not necessarily as clear and clean as you like. But most importantly what you have is a roomful of people who are supporting the Democratic Party and supporting Hillary Clinton."
Bernie Sanders tried to calm tensions among his delegates, but some weren't in a listening mood.
"We have got to defeat Donald Trump, and we have got to elect Hillary Clinton and Tim Kaine," Sanders said to supporters earlier Monday, who responded with a chorus of boos.
Sanders is scheduled to speak Monday night, as are First Lady Michelle Obama and Massachusetts Sen. Elizabeth Warren.
Other scheduled speakers and podium appearances on Monday include California state Senate President pro Tempore Kevin de Leon, D-Los Angeles, U.S. Rep. Linda Sanchez, D-Norwalk.
Actress Eva Longoria will introduce a speech by Sen. Cory Booker, D-NJ. Comedian Sarah Silverman and Sen. Al Franken, D-Minn. are expected to introduce a performance by singer Paul Simon. Other scheduled performers include Demi Lovato and Boyz II Men.
WATCH: ABC News coverage of the Democratic National Convention
The Associated Press contributed to this report.