Dershowitz is really full of sh!t on this issue. A law professor who advocates "preventive detention, anticipatory mass inoculation, prior restraint of dangerous speech, targeted extrajudicial executions of terrorists and preemptive military action including full-scale preventive war" on one hand, after having publicly stated in the past that he wants the Second Amendment repealed, is not to be trusted.
I haven't seen that, but if he has that's a perfectly sound position. If you want to rid the country of gunowners, you amend the Constitution, you don't pretend it's not an individual right. Same with Roe/Wade, supporting an amendment from either side is appropriate.
What you said.