Let me finish tonight with this.
We just learned today that more non-Hispanic whites in the U.S. died last year than were born. It's a remarkable statistic.
Obviously, people from different groups will have different reactions.
White people may feel their position narrowing somewhat, minorities may feel their position is growing; immigrants may feel the country is getting more diverse down the road.
The vital fact is that the country's demographic face is changing.
We are becoming much more like the "Many Faces of Benetton" ad.
We are getting more like the picture you get of America when you visit a city rather than when you're in the countryside - more differences of appearances, more apparent differences in background, perhaps in values and politics as well.
But the challenge remains: to build unity out of differences, e pluribus unum, one from many.
What's changed is that the pluribus is growing; growing with it is the challenge, the increased challenge of becoming "one."