Democratic rockstar Rep. Beto O’Rourke could pose a major threat to the democratic socialist movement led by Bernie Sanders should the Vermont senator decide to mount a second bid for the White House in 2020, a prominent liberal writer argues.

New York magazine scribe Jonathan Chait pitted O’Rourke, 46, against Sanders, 77, in a piece Friday, outlining how the outgoing three-term Texas congressman’s more centrist policy positions detract from the mission of supporters of the independent senator, who caucuses with Democrats, to move the Democratic Party further to the left. Chait also wrote how comparisons between O’Rourke and former President Barack Obama were giving pause to those who felt the so-called “Bern” during Sanders’ unsuccessful run for the party’s 2016 presidential nomination against Hillary Clinton.