Democratic presidential candidate Sen. Bernie Sanders (I-VT) said Thursday that President Barack Obama—not for lack of trying—has been unable to leverage his “presidential leadership” to bridge the gap between Congress and its constituents.

“There’s a huge gap right now between Congress and the American people. What presidential leadership is about closing that gap,” Sanders told MSNBC’s Kasie Hunt in a preview of an interview set to air Thursday night.

Sanders told Hunt that Obama has not succeeded in closing that gap.

“I mean, I think he has made the effort,” Sanders said. “But I think what we need, when I talk about a political revolution, is bringing millions and millions of people into the political process in a way that does not exist right now.”

Sanders said advancing his own campaign promises would require mobilizing “millions and millions of people” to get into politics and engage with their government.