Sen. Bernie Sanders (I-Vt.) hosted former Democratic vice president Al Gore for a live interview on Thursday morning.

In addition to talking about Inconvenient Sequel, Gore’s forthcoming follow-up to his groundbreaking 2007 documentary An Inconvenient Truth—both centered on the issues of climate change and energy—Gore credited Sanders with proving that a presidential campaign built on small-dollar donations could actually succeed. That’s what is needed, Gore said, “to revolutionize our politics.”