Emancipation of the servile class in Europe with the rise of the nation-state under the advance of the Enlightenment resulted in equality before the law but not in equality of condition. Equality of condition was achieved only in America, where the Constitutional order created what amounted to a classless society.
That class system in Europe translated for the Jews into a pro forma legal equality but served up an actual situation that maintained the Jews as a distinct segment of the social order, with some Jews retaining their priveleged status in the courts of power.
Europeans in the 19th and early 20th centuries defined themselves in terms of their class membership more than by their national identity or by their citizenship in the nation-state. The European ruling class and its wealthy class replaced the European aristocracy of the ancien regime but the class division in Europe remained intact until after the First World War. Only the Jews remained identified with the apparatus of the state rather than with that of a class.
The Jews' special status in Europe meant they could never blend into membership of any European class; they could hitch their wagon only to the privileges of state-craft. Class divisions were part of the social order in Europe; and Jews, notwithstanding their achievement of legal equality, could not gain entry in the social mechanisms that defined the functions of class membership.