Former Chicago Mayor Rahm Emanuel said Hasan Piker has a right to his own opinions, but people are also free and obligated to call out speech they consider hateful.

Piker, a popular Twitch political streamer who has become a visible figure on the Democratic Party’s left flank, has campaigned and appeared with progressive candidates ahead of the November midterm elections. His political activity has drawn particular attention in Michigan, where he campaigned with Democratic Senate nominee Abdul el Sayed during the primary. El Sayed has since sought to distance himself from some of Piker’s comments, as Republicans have made the streamer a central part of their attack on his candidacy.