Democratic presidential candidate Beto O’Rourke on Thursday leveled some of the most aggressive criticism of front-runner Joe Biden of anybody in the 23-person field, calling the former vice president a “return to the past” and highlighting his recent flip-flips on policy issues.

“You cannot go back to the end of the Obama administration and think that’s good enough,” O’Rourke told MSNBC when asked why he is a better candidate than the former vice president.