Brooklyn's own haredi village idiot Rabbi Yosef Mirzrachi (sometimes spelled "Mizrahi") says less than 1 million Jews were killed in the Holocaust, not 6 million, because 80% of European Jews were assimilated and most were the non-Jewish offspring of intermarriage – an insane claim if there ever was one. But Mizrachi also thinks Theodor Herzl (b.1860,d.1904) lived 120 years before the Holocaust.
A greater idiot has never walked the face of this earth:
While assimilation was high in Western Europe along with Budapest and Warsaw (but much, much lower in other places in Poland), that didn't mean these assimilated Jews married non-Jews. For every intermarriage there were literally hundreds of marriages of assimilated Jews with other assimilated Jews.
If you're interested in learning about the fate of "1/4 Jews" or "1/8 Jews" under Hitler, read Bryan Mark Riggs book Hitler's Jewish Soldiers. If you want to know how the Holocaust actually worked, you can read up on it at the US Holocaust Memorial Museum's website or at Yad Vashem. For Theodor Herzl, start here.
[Hat Tip: Zevi Chaim.]