Avi…
The government can’t compel anyone to participate in a same sex marriage. The only participants are the two people getting married. The clerk who issues the license is not a participant in the marriage. The officiant is not a participant in the marriage. The baker selling a celebratory cake is not a participant.
When new neighborhoods were being built to accommodate the post-WWII baby boom, it was not about living among anti-semites. Groups of Jews sought to buy unoccupied land and build new Jewish communities including shuls, schools and shops. This happened to my parents and a group of 20 families who were repeatedly legally stopped.
As for halacha requiring Jews who own businesses to give preference to hiring Jews. Dina Malcusa Dina. If you choose to live in the USA you agree to abide by the laws. This isn’t Tzarist Russia or the USSR where Jews were kept in by force. If you don’t like the laws, work to change them through the political system or leave.
I am amused by your comments about Jewish Communists marrying other Jewish Communists. In most cases they weren’t free to marry anyone else but another Jew because of government or church regulations in the old country. That USSR identity card carried a mark of religious/ethnic identity. The first generation of communists in Russia/USSR came at a time when the vast majority of citizens were members of the Russian Orthodox Church and rabid anti-semites. They had no interest in marrying Jews..Communist or not.