BUDAPEST, Hungary -- What do you do when you learn you are not the person you thought you were, when you learn you are the very thing you hated? It was a question Csanad Szegedi was confronted with -- one that led to a remarkable transformation. Szegedi was once a rising star in Hungary's third largest and most controversial political parties, Jobbik. Jobbik has been labeled fascist and anti-Semitic. Its leader once asked for a list of all the Jews in Hungarian government. And Szegedi, still in his 20s, was on a trajectory to lead the party someday. "I joined...