Actor, director and producer Robert Redford left the Utah center of his Sundance Film Festival to hold court at the Walker Art Center Cinema Saturday night.

In a conversation with film critic Amy Taubin, he discussed more than 40 years as a Hollywood icon and passionate supporter of independent film. Amid clips from his career, they also explored his work as a social, political and environmental activist.

“I can’t believe how important a role the environment made in it,” Redford said of “Butch Cassidy and the Sundance Kid,” a 1969 Western shot in national parks in the West. “It was terrific to film there amid these incredible geological formations.”

Redford became an actor unexpectedly, he said, and has not always felt comfortable. His first acting job was nothing more than standing on the stage in a quiz show and getting booed.

In the 1970s, his growing celebrity made him concerned about being considered a glamorous object and “behaving like one, then becoming one.”

His first film as a director, based on Minneapolis novelist Judith Guest’s bestseller “Ordinary People,” won him an Oscar. He felt it was about “people at the top of the ladder” concerned about impressing others “by doing everything right. … That was a story I wanted to tell.”

His political films “All the President’s Men” and “The Candidate” addressed the ways in which “politics can shift integrity,” he said. “The powers inside are so powerful; you can’t believe how powerful they are until you try to change them.

Later, he added: “I’d like to play Donald Trump. Films usually do deal with issues of their time.”