The idea of “two Americas,” one rich and one poor, one blue and the other red, has been around for decades. But now, thanks to Donald Trump, there are about to be fifty Americas.

Since Taglit-Birthright Israel began in December 1999, the program has sent over 650,000 Jewish young adults to Israel from 67 countries, all 50 U.S. states and Canadian provinces, and from over 1,000 ...