MILWAUKEE (Nexstar) — Democrats kicked off night one of their virtual convention in Milwaukee on Monday. Former rivals united behind former Vice President Joe Biden – attacking President Trump for the way he has handled the coronavirus pandemic.

On Tuesday, the theme is “leadership matters” and the convention starts to take up the business of approving the party’s “platform” and nominating their candidate.

“I don’t know that the American people will necessarily see it because it usually happens behind the scenes,” said Moe Vela, a former senior adviser to Vice President Joe Biden.

Vela says on Tuesday the nearly 4,000 democratic delegates attended virtual meetings to decide where the party stands on the issues this November. Vela says the platform is a compromise between the moderates in the party and the progressives — like Vermont Senator Bernie Sanders.

“Develop their platforms, the issues that matter to them—that are important to them. And then these will go on to reflect the party platform,” Vela said.

“To everyone who supported other candidates in the primary and to those who may have voted for Donald Trump in the last election, the future of our democracy is at stake,” Sen. Sanders said.

High-profile Democrats will take the virtual center stage on Tuesday night, including Bill Clinton, Jimmy Carter and former Second Lady, Dr. Jill Biden.

For the last item of business on Tuesday night, Democrats will formally select Joe Biden as their nominee for president in a prerecorded roll call vote.