American Progress: Today, hundreds of mayors are convening in Dallas, Texas, for the 82nd annual meeting of the U.S. Conference of Mayors. Climate change will play a prominent role on the meetings agenda because these mayors understand that the nations cities and towns are the front line of the response to climate change. This meeting comes on the heels of the U.S. Environmental Protection Agencys, or EPAs, recently unveiled Clean Power Plan, which proposes carbon-pollution limits for the nations existing fleet...