What makes a person Jewish? A Jewish ancestor? A Jewish upbringing? A German sounding last name? A Jewish sounding first name? A Mediterranean physique?

There are people in Africa, India and China who regard themselves as Jewish, although they have the same physique as the locals.

In my opinion a person is Jewish if he or she regards him/herself as such, identifies with the Jewish community and its traditions and teachings. This will affect your political outlook and that's what's relevant here.

Lenin was not Jewish.