Soros is a second generation atheist, a declared Magyar, and a former member of the Arrow Cross; not a Jew.
According to the wonderful Dennis Prager and others, "Jewish" is an ethnicity and "Judaism" is a religion. Do a Google search and you will find the same information. One is a Jew by birth in the same way that one is Italian, German, Polish, English, etc., by birth. Ethnic Jews may or may not practice the religion of Judaism, and people of other ethnicities who convert to Judaism are Jews in the religious sense. Karl Marx was an ethnic Jew by birth, yet he hated the Jews. This is fact, not a slur in any way.
It is also a fact that a great many Jews are politically left of center all the way to communist. Why that is so is, to me, perplexing. For whatever reason, they believe in statism despite the fact that all-powerful states have done enormous to harm Jewish people throughout history.