There is a natural greenhouse effect that contributes to warming. Greenhouse gases trap heat and thus warm the Earth because they prevent a significant portion of infrared radiation from escaping into space.

We can't allow the world's worst leaders to blackmail, threaten, hold freedom-loving nations hostage with the world's worst weapons.

We will allow private and religious groups to compete to provide services in every federal, state and local social program.

Nearly all Americans have ancestors who braved the oceans - liberty-loving risk takers in search of an ideal - the largest voluntary migrations in recorded history... Immigration is not just a link to America's past; it's also a bridge to America's future.

I may be the only person, the only presidential candidate who never carried the state in which he was born.

There are prayers that help us last through the day, or endure the night. There are prayers of friends and strangers, that give us strength for the journey. And there are prayers that yield our will to a will greater than our own.

After the bombing, most Iraqis saw what the perpetuators of this attack were trying to do.