If half-black Barack Obama had decided years ago to call himself white - which his genes certainly entitled him to do - his story would have carried very different meaning. If millions of part-black people had followed him into whiteness, then the N.A.A.C.P. would be in true crisis.

The boomers will eventually have to accept that it is not possible to stay young forever or to stop aging. But it is possible by committing to show up for each others in community after community, to earn a measure of immortality.

The Boomers have modeled a set of bad habits, and one grand gesture is not going to unwind all those bad habits.

Today's multiracial Americans are at greater liberty to choose how they'd like to be seen, and under less pressure to pass for white.

Our commitment should be to leave our environment in better shape than when we found it, our nation's fiscal house in better order, our public infrastructure in better repair, and our people better educated and healthier. To indulge in immediate gratification and exploitation is an insult to previous generations, who sacrificed for us, and thievery from the next generation, who depend on our virtue.

Here's a proposal, offered only partly in jest: no resident of the United States, whether born here or abroad, should get to be a citizen until age 18, at which time each such resident has to take a test.

In the end, a new Americanization movement can't just be about listing our privileges and immunities, which we catalog in our laws. It also has to be about reinforcing our duties, which we convey in our habits.