Local and state governments have outrun the federal government. The EPA has served notice that it will enact a rule requiring CO2 reductions by major emitters in the absence of major legislation. But it's a blunt instrument that is a little more difficult to use than a legislative remedy.

Well-established theories collapse under the weight of new facts and observations which cannot be explained, and then accumulate to the point where the once useful theory is clearly obsolete.

Take it from me, every vote counts.

I was born a poor black child.

Our world faces a true planetary emergency. I know the phrase sounds shrill, and I know it's a challenge to the moral imagination.

I was in elective politics for 24 years. I've made four national races, two for president, two for vice president. I have found there are other ways to serve, and I'm enjoying them.

I'm still trying to figure out exactly what President Trump represents in American politics. But, if nothing else, he represents a way for tens of millions of people who were desperate for change to just turn the table over and say, we want to start over again. But it is a challenge for our democracy. It definitely is. But, again, the remedy has to be devoting enough attention to restoring the way we make collective decisions in this country.