I agree with the gorilla. In 1948 social antisemitism was quite OK, restricted towns and communities, blatant discrimination in hiring, quotas of colleges and professional schools and so forth. In spite of all that very few Jews left the USA to settle in Israel, basically because they felt the lifestyle in the USA was better, in spite of the antisemitism, and they saw things as improving for them. Assume that the McvCarthyism was stronger and had a stronger antisemitic component than it did painting all Jews as reds and pinks and anti-American. This leads to limits on Jewish in employment in state and federal civil service, not allowed as officers in the military (but can be drafted as enlisted, but like blacks pre-desegregation only in service/labor units), numerus clausus laws which limit the percent of Jews in law, medicine, etc (a traditional thing in Europe before WWII). You begin to see people like the Klan torching synagogues, or trashing Jewish retail businesses. With this you might very well see a massive emigration of Jews to Israel from America as the Jews of the USA would see this as an analogue of the early 30s right after the Nazis took over and decide to get out while the getting was good...