system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why are Jews treated more like a race than other religions?

Thanks Everyone!!! I really learned a lot today and have a new deeper appreciation for Jewish heritage.

edit: we got locked, probably for the best as there was not much more that could be added. Thanks to the mods for moderating.
gpt
Jews were treated like a race because, for centuries, they behaved like a race and were treated like a race.  Let me explain.  The answer is genetic and has to do with the fact that most Jews originated from one and the same relatively small number of Jews who lived in Israel two-thousand years ago.  
   For a long time this was mere conjecture but genetic testing now demonstrates this beyond a doubt:  an American Jew shares a greater genetic pool with an Ethiopian Jew than they do with their non-Jewish countrymen and this common genetic pool is about two millennia old.  Now, obviously, everyone on earth traces their ancestry to some group that lived somewhere 2000 years ago.  The difference is that Jews, for religious reasons, remained relatively strict about intermarriage.  A variety of rules (such as kosher diet or sabbath observance) kept them together as a closely-knit community, even when they were dispersed from Israel (in what Jews call "the Diaspora").  So unlike, say, Goths or Huns, who shared the same group of origin but were "mixed in" thoroughly with the surrounding population in the centuries that followed their dispersal, Jews even in exile maintained a relatively "closed" genetic circle that is still detectable.  Some outsiders have joined this group (hence, blonde Jews here and dark skinned Jews there) but that number is very small and intermarriage was, until recently, very small, in part due to exclusiveness (by Jews towards outsiders) and racism (by outsiders towards Jews).
   Hence:  Jews are treated like a race because, for centuries, they were treated like a race.