The Census Bureau forecasts that the U.S. will become a minority-majority population for the first time in 2043, according to its first set of new population projections based on the most recent 2010 U.S. Census,
This means that non-Hispanic whites will, for the first time, comprise less than 50% of the population.
At that point, there will not be a racial majority in the United States.
The Census Bureau attributes changes to projected fertility levels and international migration.
Additionally from the Bureau’s report:
All in all, minorities, now 37 percent of the U.S. population, are projected to comprise 57 percent of the population in 2060. (Minorities consist of all but the single-race, non-Hispanic white population.) The total minority population would more than double, from 116.2 million to 241.3 million over the period.