Former President Bill Clinton scrapped a version of his speech after the watching the first night of the convention, several people familiar with the speech told ABC News.

Clinton, who is speaking Wednesday night, revised his speech to make sure the "substance meets the moment" and wanted to strike a more "joyful" tone, after he was struck by the energy of the convention floor, one source said.

A senior adviser to Clinton told ABC News that "it was clear to him that, in the spirit of Mario Coumo, we needed more poetry, not prose."

Cuomo gave the keynote address at the 1984 Democratic convention, saying, "We Democrats must unite so that the entire nation can unite, because surely the Republicans won't bring this country together."

-ABC News' Rachel Scott and Katherine Faulders

Actress Mindy Kaling is tonight's celebrity host.

In 2019, she and Harris went viral for a video in which they prepared masala dosa, a South Indian dish.

In her introduction, Kaling referred to herself as "the woman who courageously outed Kamala Harris as Indian in an Instagram cooking video."

Democrats have already brought out multiple celebrities Wednesday, including musical legend Stevie Wonder and comedian Kenan Thompson. The crowd roared each time in surprise.

John Legend will also perform later.

Both parties have used celebrities, including wrestler Hulk Hogan at the Republican National Convention.

Veteran "SNL" actor Kenan Thompson performed a bit of a stump speech and variety skit at the DNC that poked fun at "Project 2025."

Thompson brought the prop "Project 2025" book and talked with people across the country about how the conservative policies would harm them drawing boos and laughs from the crowd.