The government also has to get the public rules right. That means putting a price on carbon, so the cleaner forms of energy become more competitive. As soon as that happens, a tidal wave of new capital, innovation and entrepreneurship will flood into the clean energy space - creating new jobs and opportunities for Americans of all walks of life. We did that for the internet, with public investments in the basic system through the Pentagon, followed by rules that encouraged innovation and competition. And that is why the internet took off in the United States first.

Dirty energy is a finite resource; the more of it we use, the scarcer it becomes.

There are only two ways to have a middle class in your country: either you have highly skilled manufacturing jobs, or you have a highly skilled, well trained, knowledge-based workforce. In other words, college.

We seem to forget that everything that is good for the environment is a job. Solar panels don't put themselves up. Wind turbines don't manufacture themselves. Houses don't retrofit themselves and put in their own new boilers and furnaces and better-fitting windows and doors. Advanced biofuel crops don't plant themselves. Community gardens don't tend themselves. Farmers' markets don't run themselves. Every single thing that is good for the environment is actually a job, a contract, or an entrepreneurial opportunity.

Donald Trump was underrated, but he understood social media and he understood reality television.

I learned more in those six months [ in the White House] than in the prior six years. I don't think that anybody who has had the privilege to serve the country at that level should walk out and behave like a crybaby. And I plan to continue to serve the country in other capacities.

The time has come for a public-private community partnership to fix this country and put it back to work.