At a Democratic campaign event in Iowa where she introduced 2020 presidential candidate Sen. Bernie Sanders, actress and left-wing political activist Susan Sarandon threw a not-so-veiled jab at his progressive rival, Sen. Elizabeth Warren: “He is not someone who used to be a Republican.”

Sarandon, who was a fervent Sanders supporter in 2016 — and who went on to advocate and vote for Green Party candidate Jill Stein instead of Clinton — remains one of the Vermont senator’s most outspoken fans. Warren has not ducked the fact that she was a registered Republican up through the mid-1990s, and has explained several times why she switched parties and moved to the left politically. Sanders remains an Independent in his Congressional affiliation, but back in March as he kicked off his 2020 campaign, he signed a Democratic National Committee loyalty pledge that said: “I am a member of the Democratic Party.”