Recent breathless accounts of new U.S. Census data and accompanying projections have indicated that, goodness gracious, whites will not be a majority of the American population within a generation. No kidding. In San Mateo County and the rest of California, that’s been the case for awhile when it comes to those of school age. In fact, whites aren’t even the biggest ethnic group anymore. Here on the Peninsula, Hispanic children made up 33.9 percent of the total public kindergarten-through-grade 12 student body in 2006-07, the most recent year for which statistics are available from the California state Department of Education. White pupils represented 33.7 percent. Asian and Filipino kids were next at 11.9 and 9.9 percent respectively. Black youngsters were 4.2 percent. It is fully anticipated that these trends will persist. That is due mainly to a continuing flow of immigrants (legal and illegal) to the area and higher birth rates among those newcomers, especially Hispanics.