I would say I would disagree because private school teaches us politeness, have a good teacher to make us more better, make a lot of projects, join a lots of competition, and gave idea and chances to other students to learn.
Imagine a regular person runs for office, owns a few index-fund shares from before, and now must dump them or set up a trust just to serve. That hassle could keep normal people out of politics. My opponent has a fair point, but I am not sure a ban is right.