Thanks for the link. It seems like it was a softball no-brainer question. Of course he is going to say he opposes antisemitic protests. Any other answer would have been picked apart.
As far as I know, there are no 'Antisemitic protests happening"
Well, first, I will note that in the article linked by the OP, there are pro-Palestinian protesters distancing themselves from some other protests that have sprung up around it, seemingly due to their antisemitism. Additionally we have both claims and videos of people protesting around Columbia throwing out clearly antisemitic shit, like telling jewish people that “the 7th will be every day for you.”
Second, the POTUS does not know everything all of the time. If he had been more nuanced and said “well those protests weren’t antisemitic” and then someone found someone being antisemitic, it would be a political shitshow. His answer to the question asked is pretty much the only sane one. And, more importantly, it certainly does not indicate that he thinks or is implying that any protest of Israel is antisemitic. I would argue that also bringing up Palestine and their suffering right after that indicates and implies he does not think that at all.