If someone is going around targeting jewish people, because they don't like Israel, they are a rasits.

the article the professor hasn't displayed any bigotry towards Jewish people

Yes he did. He targeted jewish students. It is racist iregardless of his reasons for it. In the same way that if you kick out black people from your store, because you are protesting African warlords, you are still a racist.

There are some actions, such as targeting students, that are racist irregardless of a person's reason for engaging in them.

If he wanted to protest israel, he should feel free to speak out, or even never visit israel, but the moment he targeted jewish students, he became a racist.