PHILADELPHIA - The Democratic National Convention began Monday afternoon in Philadelphia, and Democrats were scrambling to unite the party after leaked emails indicated that top officials at the DNC worked to undermine Vermont Sen. Bernie Sanders' presidential campaign in order to help presumptive nominee Hillary Clinton.

Sanders was the last to take the stage on Day 1 of the convention Monday night. Divulging his disappointment in not being the Democratic presidential candidate, he thanked all those who supported his campaign. And with some of his supporters in tears as he spoke, the runner-up outlined the progressive proposals he had championed throughout his primary campaign. Sanders ended his speech by again voicing his support for Clinton, saying he is "proud to stand with her" and that she must be the next president of the U.S.

Speaking before Sanders, Michelle Obama delivered an impassioned speech in which she threw her support behind Clinton.

"I am here tonight because in this election there is only one person who I trust with that responsibility, only one person who I believe is truly qualified to be president of the United States, and that is our friend Hillary Clinton," the first lady said.

Obama and Massachusetts Sen. Elizabeth Warren also called for unity among the Democratic Party.

As Day 1 of the convention began, a palpable sense of chaos was already present. Debbie Wasserman Schultz, the chairperson of the Democratic National Committee, is out and did not even gavel in the convention. Her resignation is the result of a series of emails appearing to show DNC staffers plotting against Sanders' campaign during the primary. But despite the revelations, Sanders says his endorsement of Clinton still stands. Many of Sanders' supporters, however, would not say the same.

"The delegates are here to support Bernie Sanders," said Kacey Carpenter, a Sanders delegate from California. "Bernie has asked us to continue the revolution."

A week after Republicans fought off doubts about the unity of their party, it is now the Democrats who must work to fend off those same questions. House Minority Leader Nancy Pelosi said she believes that once the convention is over, members of both the Clinton and Sanders camps will be able to share one tent.

"I do believe that we will win the White House, we will win the Senate, we will win the House of Representatives, we will win the state houses across America and the state legislatures, because of the vitality of both the campaigns - Hillary Clinton, and the campaign of Bernie Sanders," Pelosi said.

For now, though, the Democratic Party is not one big, happy family. In fact, a number of Sanders supporters shouted down some pro-Clinton speakers on stage.

Steven Abreu, a Sanders delegate from Plainview, said that despite calls from Sanders for his supporters to back Clinton, he won't do it, at least for now.

Hofstra University political analyst Larry Levy added that Sanders has a tough task ahead of him.

"You're going to see a full-throated endorsement of Clinton," Levy said. "It may come at the end of a long speech that talks about all that Sanders believes he's accomplished, but Sanders is going to be there backing her."

It remains to be seen whether the so-called revolution is loyal to the man who brought it to the forefront, or if Sanders supporters will continue to speak against Clinton at the convention.

Meanwhile, Clinton was campaigning in Charlotte, North Carolina Monday as the convention got underway. She said she looks forward to addressing her party and the American people during her big speech Thursday night.

On Tuesday, the official delegate vote tally will take place. While Sanders is clearly supporting Clinton at this point, he said that he is looking forward to hearing his delegates call his name.