Obama used the former rather than the latter phrase last night and I heartily approve.  Consistently in his public life he has talked about complementing our famed American individualism with the promise that we have to make sure that all of us have the opportunity to pursue our dreams and that we treat one another, future generations, and our planet with respect so that our common life is rich and of high quality.

He is of course right.  This is the core point the people who call themselves communitarians make.

The double meaning of The American Promise reinforces the point. 

The "Promise that is America" is that, when we heed those better angels of our nature, we act to improve our world ever closer to one where there is a valued place and opportunity for all of us to live full and rich lives.  

A promise is also something that is made between people.  Using that word--promise instead of dream--treats the social nature of human life and the reciprocal obligations necessary to a successful society and world as of central importance. 

The formulation that had been in my head of late is marrying The American Dream, which has a more individualistic connotation, with Dr. King and others' concept of The Beloved Community, as an expression of our highest individual and communal ideals and goals.  I'm glad to say I like Obama's better.