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.

Many vulnerable Democrats have skipped the convention in Chicago -- but not Marcy Kaptur.

The Ohio Democrat, the longest-serving woman in congressional history, now represents a much redder seat after redistricting.

A spokesperson said she traveled to Chicago today to hear Walz -- her former House colleague -- in person after calling for Harris to choose a running mate from the heartland.

Her presence underscores how the new Harris ticket has reenergized Democrats and given even threatened members of the party hope that they can defend their seats in November and retake the House of Representatives.

They see Walz as one of their own: While he served in Congress, he was one of the few House Democrats to win reelection in a district that supported Donald Trump. (Democrats lost the seat when he ran for governor in 2018.)

-ABC News' Rachel Scott and Benjamin Siegel

Kim is the third Democratic Senate candidate to address the DNC, after Angela Alsobrooks and Lisa Blunt Rochester. All three are running in safely Democratic states. By contrast, vulnerable Democratic senators like Tammy Baldwin of Wisconsin and Jacky Rosen of Nevada are staying away.

—538’s Nathaniel Rakich