@oralloy,
First these people are not necessarily anti semitic , but rather anti Israeli. Even the ones who claim to be "pro - Palestinian but not anti Israeli" are indeed anti Israeli . Pro- Palestinian is by definition anti Israeli.
Plus, what these students are America's future leaders , law makers , voters , and most important - public . And if today they support Palestine - they'll do so in the future. An Israeli won't be safe in a pro-Palestinian America.