Since the 1930s, Hungary has been an anti-Semitic state. During World War II, the Hungarian fascist equivalent of the SS was the Arrow Cross, a group that loved sending Hungarian Jews to concentration camps.
When the Russians took over Hungary, they didn't spend a lot of time reeducating the Hungarian people on their attitudes towards Jews. Russia was not as anti-Semitic (hard to believe, huh) but it wasn't an issue of importance to them.
My daughter is the granddaughter of Hungarians who are Holocaust survivors. I once took a trip with them to Budapest and heard stories of cabdrivers who would refuse to carry Jews in their cabs. People like Tony Curtis gave money to rehabilitate the synagogue in Budapest, and George Soros bought the best restaurant there. But it made little difference. Hungary was too attached to the practice of hating Jews.
Since 2002 Hungary has moved to the right and become more authoritarian under Prime Minister Viktor Orban. The far right Jobbik party controls nearly 20% of Parliament and has a nationalistic anti-Semitic platform.
Things are not getting any better, even though Ivan Fischer, the conductor of the Budapest Festival Orchestra, recently premiered an Opera called the "Red Heifer" which is a rebuke of antisemitism.
Hungary's attitude is a stain on Europe. Allowing Hungary to participate in European integration, is to let the camel's nose under the tent. If the Europeans don't address this serious problem there is a lot of trouble coming down the road. I've always been surprised at how easy it is to revive antisemitism. For some reason "it's the gift that keeps on giving." I'm a goy, but for me antisemitism is the most frightening concept I can think of.