No, Jews are not a "race." Neither are Mormons, Muslims, Blacks or Whites, for that matter. There is no such thing as "races" of people. Any discussion of what is a "race" is as far from reality as a debate over the difference between trolls and goblins. What exists is racism - the mass hallucination that people are divided into races, and the disparate treatment which arises from that social disease. Hitler was insistent that Jews were a race, not a religion, which is why Whoopi Goldberg's comment that the Holocaust was not "about race" is completely wrong.

As to a law that "singled out Jews for worse treatment" I can point you to a chapter of my book, A History of California Labor Legislation: Revised and Updated Centennial Edition (Queen Calafia Publishing 2012). Chapter XIII is about the "Sunday Laws" which require businesses to observe Sunday as a Sabbath (without giving the workers a day off, though). This was upheld by the Supreme Court in McGowan v. Maryland, 366 U.S. 420 , 81 S.Ct. 1101, 6 L.Ed.2d 393 (1961). The separate opinion of Justice Frankfurter, beginning at 81 S.Ct. 153, provides an extensive historical review of these laws, as well as a compilation of those still in effect at the time. If you read the first chapter of Brodkin's book, she reviews many other examples.