I have complete confidence in Secret Service. These guys and gals are unbelievably professional. They know what they’re doing and I basically do what they tell me to do. Now, sometimes I’m the first one to admit that it chafes a little bit being inside this bubble. It’s the hardest adjustment of being president, not being able to just take a walk.

We lose ourselves when we compromise the very ideals that we fight to defend. And we honor those ideals by upholding them not when it's easy, but when it is hard.

For we know that our patchwork heritage is a strength, not a weakness.

For now, decisions are upon us and we cannot afford delay. We cannot mistake absolutism for principle or substitute spectacle for politics, or treat name-calling as reasoned debate.

Here at home, we will strengthen our defenses but not succumb to a siege mentality that sacrifices the open society and liberties and values that we cherish as Americans, because great and proud nations don't hunker down and hide behind walls of suspicion and mistrust.

A political candidacy built around hope and change and compromise would eventually become a presidency of crisis and confrontation.

Let's remember that our leadership is defined not just by our defence against threats, but by the enormous opportunities to do good and promote understanding.