That criticism always tends to remain in vague territory. You pretty much never see a leftist try to debate the specifics of a point Shapiro has made. They just don't like him. Shapiro has gotten into plenty of debates with people more qualified than college kids as well.
There are hour long debunkings of his tripe on climate change and healthcare which have been posted here before.
They aren't exactly anyone magna opus but they couldn't really be given the source material they were working with - that is to say Shapiros arguments are mostly vapid on their face and break down under any real scrutiny.