It is kind of like when people say some blacks are Uncle Tom's because they scrape to the white man. Uncle Tom as conceived by Harriet Beecher Stowe is not a black man who scrapes to the white man, but the Christlike figure who dies for all our sins. That was the way pre civil war Americans understood him to be.
Thanks, Stephan. Nevertheless, I know some of the FReepers take it as Jews disparaging gentiles.