There are no rules in America specifically banning antisemitic speech. One can find it in many places. In Europe, however, there is becuase the NAZI's laid waste to the continent. in the 1930's and 1940's. They are not to keen on repeating WWII. Anti-Muslim speech is every bit as abhorrent, but it doesn't carry the same historical baggage for Europeans.
Turkish jets take part in U.S.-led coalition strikes against ISIS for first time (Reuters)
from the article: Helen Thomas cancels participation in anti-AIPAC event