Tell your black children that lots of white guys who were President only were elected to one term as well. Race has nothing to do with it.
And like in 2008 America showed a black man could be elected President, in 2012 America will show that a Mormon could be elected President. Eventually we'll have a female President, a Jewish President, a Hispanic President, and an Asian President. Those things will happen when people of those arbitrary cultures rise to national government leadership levels.