Barack Obama: “The threat from Iran's nuclear program is grave.”

In forming our union, the founders fell terribly short of the Declaration's promise, leaving slavery intact, allowing states to restrict the franchise to white men who owned property.

Every president here today, as different as we are, has tried our best to uphold the values that John McCain and Mitt Romney believed in no less than I did.

They're meant to remind us of who we can be, to remind us of what's possible, so we can forge ahead.

No one was more skilled at bringing people together and getting legislation passed.