The fascination with millennials appears to be never-ending, as evidenced by the media's focus on their politics, lifestyles and taste in pop culture. But it is fair to say that the most important societal attribute of this giant generation is its far greater racial and ethnic diversity. Indeed, the millennials constitute a demographic bridge between the white-dominated America of yore and its multiracial future.

New Census information spells this out in just a handful of stats. In 1990, nearly three-quarters of young adults defined themselves as white. Today, just 56 percent are white, and in contrast to the pre-millennials, "new minorities," including Hispanics, Asians and persons of two or more races, make up the lion's share of non-whites.

In fact, whites already constitute less than half of millennials in 10 states and Washington, DC. In California, more than two-thirds of millennials are non-white. Texas, Florida, Georgia and New Jersey aren't far behind.

The aforementioned bridging function of millennials is apparent when looking at the post-millennial population (now below age 18): they are 48 percent non-white. Since 2000, the aging of the white population combined with the relatively low fertility rate of white women of child-bearing age has led to an absolute decline in the number of white youth. Thus minorities (Hispanics, Asians, blacks and others) constitute all of the growth in America's child population.

So as millennials move into positions of leadership, both public and private, they will pave the way for a nation that will look nothing like the world of Ozzie and Harriet. Tomorrow's "middle America" will be a truly multiracial and multicultural, and it will be up to millennials to define what that means.