I've got certain responsibilities that I have to carry out in a very specific institution and in a specific moment in time.

I think there are a lot of people who are involved in the Tea Party who have very real and sincere concerns about spending that's out of control or generally philosophically believe that the government should be less involved in certain aspects of American life rather than more involved. And they have every right and obligation as citizens to be involved and engaged in this process.

But today, just a few years into the twenty-first century, we already find ourselves in a different and precarious position. As revolutions in communications and technology have broken down barriers across the world, it has given more power to both our competitors and our enemies.

We cannot stop every act of senseless violence. We cannot know every evil that lurks in troubled minds. But if we can prevent even one tragedy like this, save even one life, spare other families what these families are going through, surely we've got an obligation to try.

When Michelle and I decided that I would run for President, it was because of a shared belief in the power of community and connection, a commitment to the idea that we are our brothers' keepers.

The terrorists do not speak for over a billion Muslims who reject their hateful ideology.

Weapons of war have no place on our streets.