What I want to do is make sure middle class kids, not Donald Trump's kids, get to be able to afford college.

The middle class is both real and aspirational. And I want to make sure that it remains strong and it gives people a sense of security and confidence and optimism about their futures.

The challenges of change are always hard. It is important that we begin to unpack those challenges that confront this nation and realize that we each have a role that requires us to change and become more responsible for shaping our own future.

People will be able to judge for themselves.

I'm thrilled the president [Barack Obama] has endorsed me. We started off as fierce competitors, and we've ended up as true friends and partners and worked together on so many important issues.

It's important to take criticism seriously - not personally.

You're going to get a lot of advice coming from many different quarters to do things that don't feel right to you, that don't reflect who you are and what your values are. So you have to be grounded in who you are and what you believe.