WASHINGTON—Slamming the campaign for promoting the popular podcaster’s backing, liberals said Friday that Bernie Sanders’s acceptance of Joe Rogan’s endorsement sends a dangerous message that the candidate is trying to win the 2020 presidential election. “This is just the Sanders campaign opening the gates to a plurality of people who would vote for him and help him win the presidency,” said political commentator Scott Griffin, who called the campaign’s promotion of Rogan’s endorsement a true “mask off” moment, exposing Sanders’s goal of winning the Democratic primary and eventually the general election. “It’s very unnerving to see a Democratic candidate like Bernie Sanders try to court voters from varying constituencies and demographics. It’s like his whole strategy is beating Trump. We saw hints of this in 2016, but I’m truly sickened to see it rearing its ugly head again. I’m all for creating a Democratic majority, but not if we have to accept more people than the other side has.” Griffin added that it was even more disturbing that Sanders would attempt this during an election year.