Grassroots activists have always been the foundation of the Democratic Party -- and they've been loud and clear for months with a simple demand: Put climate front and center in the Democratic debates.
I'm extremely disappointed in the decision made by the DNC to refuse to hold a climate debate and to ignore these Democrats. And I'm extremely concerned about their threat to punish candidates who would participate in an outside climate debate by locking them out of future DNC debates. It is undemocratic.