I'm not sure it made them specifically antisemitic, but it conveyed to me that someone somewhere was not as neutral as they thought/said they were, or else didn't know much history. Arafat aside, Syria under Assad ran over entire villages with tanks -- with the people still inside the houses -- and the countries surrounding Israel all kicked out the Palestinians militarily because they didn't want to deal with them, either. (According to our Visa bill when we visited East Jerusalem, the West Bank is still technically part of Jordan, but for some reason they don't seem to want it back.) Israel has made all sorts of questionable or regrettable decisions, but if they operated by the standards of their neighborhood they wouldn't have such a protracted problem because they would have killed off everyone they felt annoyed or threatened by, and not been stuck with the much thornier question of how to live with them.

Just off the top of my head, I could also add Kim Jong Il, Pol Pot, and a couple of Latin American generals to the list. It's less a matter of balancing off Sharon against Arafat (never mind whether that works or not; I'll leave that to people who know more about it) than the huge gap between Sharon and everyone else on the list, and all the big-name people who could easily fit in in between. Hitler, Stalin and Hussein also share a certain quality off killing people totally for the heck of it that I would say does not apply to either Sharon or Arafat.