Media mogul Oprah Winfrey, whose opinions can get millions of fans to try a new diet or turn a book into an international best-seller, is figuring out which Democratic candidate she will endorse in the crowded 2020 U.S. presidential race.

Winfrey, who has ruled out running for the White House, told the Hollywood Reporter in an extensive interview released on Tuesday that she was "quietly figuring out where I'm going to use my voice in support."

"I'm sitting back, waiting to see. It'll be very clear who I'm supporting," she said of the 2020 election campaign.