The good news is that we've seen in recent years significant reductions in the cost of solar panels and wind production. We know how significant an impact we can have by moving towards energy efficiency and transforming our transportation system. So we know what has to be done. We have to develop the political will to do it, and, as president, this would be an issue of huge concern to me.

It means joining with allies to deploy renewable energy technologies -- both at home and around the world -- to confront the very real and present danger of potentially irreversible climate change.

What we have seen for a very long time is large corporations shutting down plants in this country, plants that are often profitable, in order to get cheap labor all over the world. And that is one of the reasons why the middle class in this country is disappearing.We have lost our manufacturing base, and that's an issue that has got to be dealt with.

There is something fundamentally wrong about the way we [americans] are moving as a country, when billionaires are able to buy elections as a result of Citizens United. There`s something fundamentally wrong when 99 percent of all new income goes to the top 1 percent.

Don't underestimate me.

The American people must make a fundamental decision. Do we continue the 40-year decline of our middle class and the growing gap between the very rich and everyone else, or do we fight for a progressive economic agenda that creates jobs, raises wages, protects the environment and provides health care for all?

[Hillary] Clinton is too much into regime change and a little bit too aggressive without knowing what the unintended consequences might be. Yes, we could get rid of Assad tomorrow, but that would create another political vacuum that would benefit ISIS.