Protestants are losing their centuries old majority in the U.S., falling from 63 percent to 52 percent between 1993 and 2002. You can thank church dropouts, fewer children being raised as Protestants, and fewer Protestant immigrants. Some of the shift can also be attributed to people who describe themselves generically as Christians, but not Protestants, a category that didn’t exist in the 1970s but now constitutes 2 percent of the population.