Antisemitic comments are designed to shut down the alt-right.
Are you kidding? Antisemitism is a fundamental part of the alt-right.
Are you implying it's a "false flag" effort? I find that unlikely.
During my life, i've talked to a bunch of conspiracy nuts, and many of them really do believe that there is this massive "Jewish Conspiracy" against America.
You can't reason with them. They weren't reasoned into their positions, and they won't be reasoned out of them.