Sustaining the ideology of "the American dream" requires the down-playing of social and political change in other countries, and the elevation of economic prosperity--however gotten--above other types of prosperity.
American exceptionalism requires that the truths and experiences of the very constituents Obama seeks to enfranchise--the politically and economically disempowered--be painted as non-fundamental to the history, character and prosperity of the U.S. Their contradictory experiences get downplayed or silenced in favor of the grand narrative, and progress gets interpreted not as humane social action and hard political work but as the inevitable outcome of inherent U.S. American righteousness.
This is simply inaccurate. Certainly there are nations that don't do as well as the U.S. on multiple counts. On the other hand, other nations have already elected women presidents or indigenous presidents. Other nations ended slavery before the U.S., or never engaged in it at all. Other nations already offer national health care, empower labor, regulate lending institutions, and protect the environment.
No other nation in the world imprisons the proportion or the sheer number of human beings that we do. A disproportionate number are black, Hispanic and American Indian. No other nation has detonated a nuclear weapon in war killing tens of thousands of civilians.
The tired story of American exceptionalism does not jive with our knowledge of world affairs and how foundational dispossession, exploitation and violence have been to the rise of U.S. power and prosperity. Such aspects of U.S. history are not the exceptions that betray the true democratic soul of the U.S. As much as the feel-good events, these are integral to the American story and how we developed as a powerful nation.