Actor Sam Waterston was among those arrested Friday in the latest weekly D.C. climate protest led by Jane Fonda, his co-star in the Netflix series Grace and Frankie.

This was Waterston’s second arrest. He also was arrested in October when he and other demonstrators blocked First Street on the east side of the Capitol, as they did in Friday’s protest.

Fonda was not arrested, but has been on five previous occasions, including one where she spent the night in a D.C. jail. Last fall, she moved to Washington temporarily to help organize the weekly rallies and demonstrations, called First Drill Fridays, as a way to call attention to the need for urgent action on climate change.

Also participating in Friday’s rally were Iain Armitage, the star of the series Young Sheldon, and director Josh Fox.

The focus on Friday’s demonstration was on who is...