Senators Bernie Sanders, Jeff Merkley, and Ed Markey introduced their "100 by 50 Act" — designed to completely transition the United States to clean and renewable energy by 2050 — during a rally this morning in D.C.

Their biggest thing: The senators believe that the United States' position as the largest emitter of greenhouse gases gives it a moral responsibility to take the lead. "If we expect other countries around the world to listen to us, we cannot preach temperance from a barstool," Markey said.