The alternative, no limits on Iran's nuclear program, no inspections, an Iran that's closer to a nuclear weapon, the risk of regional nuclear arms race, and the greater risk of war - all that would endanger our [American] security.

Few challenges facing America and the world are more urgent than combating climate change. The science is beyond dispute and the facts are clear.

When what you’re doing doesn’t work for 50 years, it’s time to try something new.

It is that promise that has always set this country apart-that through hard work and sacrifice, each of us can pursue our individual dreams but still come together as one American family, to ensure that the next generation can pursue their dreams as well.

It's hard to anticipate. I can tell you what I'm feeling right now is that I'm busier than I expected these last two weeks. A great deal of emotion around the people that I've worked with and the gratitude I feel for the sacrifices they've made on behalf of the American people, but also on behalf of me personally.

Let me be absolutely clear. Israel is a strong friend of Israel's. It will be a strong friend of Israel's under a McCain administration. It will be a strong friend of Israel's under an Obama administration. So that policy is not going to change.

Tonight, more Americans are out of work and more are working harder for less. More of you have lost your homes and even more are watching your home values plummet. More of you have cars you can't afford to drive, credit card bills you can't afford to pay, and tuition that's beyond your reach.