You haven't seen a lot of turnover in my campaign. And the culture of my campaign is one in which I think everybody feels a great sense of ownership.

That's the true genius of America: that America can change. Our union can be perfected. What we've already achieved gives us hope for what we can and must achieve tomorrow.

Today I am pledging to cut the deficit we inherited in half by the end of my first term in office.

The issue of climate change is one that we ignore at our own peril. There may still be disputes about exactly how much we're contributing to the warming of the earth's atmosphere and how much is naturally occurring, but what we can be scientifically certain of is that our continued use of fossil fuels is pushing us to a point of no return. And unless we free ourselves from a dependence on these fossil fuels and chart a new course on energy in this country, we are condemning future generations to global catastrophe.

It's useful for activists just to be out there to keep you mindful and not get complacent, even if ultimately you think some of their criticism is misguided.

Nothing in life that’s worth anything is easy.

Throughout American history, there have been moments that call on us to meet the challenges of an uncertain world, and pay whatever price is required to secure our freedom.