What we've often seen is that when we Americans say, look, we've got to reduce pollution, business - some businesses complain about it, but almost every time, it's turned out to be easier and cheaper and accomplished faster, and they've gained confidence, and then we go farther.

I pledge to you today that as president, in my first budget, I will introduce the largest increase in special education ever.

I don't have the illusion that there's any position or role in the world with as much potential for bringing about change as that of president of the United States.

Earlier in this century, the Heisenberg Principle established that the very act of observing a natural phenomenon can change what is being observed. Although the initial theory was limited in practice to special cases in subatomic physics, the philosophical implications were and are staggering.

I'm old enough to know that a red carpet's just a rug, and I've been able to enjoy the pageantry without letting it go to my head.

The choice to 'do nothing' in response to the mounting evidence is actually a choice to continue and even accelerate the reckless environmental destruction that is creating the catastrophe at hand.

I think that more diversity is a good thing, and fresh points of view articulated by people who are committed to excellence in journalism is a beneficial change in the American media landscape.