Career
He prepared the law of Numerus clausus and submitted for the Diet of Hungary. The Hungarian Numerus Clausus was introduced in 1920. The policy is often seen as the first Anti-Jewish Acting of 20th-century Europe.
Though the text did not use the term "Jew", it was nearly the only group overrepresented in higher education.
Its aim was to restrict the number of Jews to 6%, which was their proportion in Hungary at that time. The rate of Jewish students was 25–40% in the 1910s in different faculties.
Haller became chairman of the KNEP in 1920, but soon he lost his mandate.