Those comments strikes me as outrageous Anti-Semitism, but quick Googling showed me that, surprisingly, MacDonald is a bit of a respected academic. To be frank, is this video complete bullshit or does it include any valid descriptions of Jewish immigration to the United States?
He suggests that American Jews as a group had a vested interest in "changing the ethnic makeup of the United States" and want to "end Western dominance" of global society, which I doubt is anything more than neo-Nazi fearmongering. MacDonald certainly seems very interested in "European interests", and seems to believe that white people should stay dominant in US society.
Even if every Jew in the world pre-holocaust had moved to the US that would still be only a small fraction of the total US population; anyone capable of basic math can see the proposition is ludicrous.
Unless you wish to assert that the leaders of some worldwide conspiracy couldn't do simple arithmetic.
edit: not "you" the OP, just a general "you."
Looks like his work on child development was respected, but his work on Jews went off the rails and lost him his academic reputation. He also writes for a recognized hate group (anti-immigrant/white supremacist group) VDARE, which likely lost him even more cred.
MacDonald is not respected as an academic any more. He is a vocal white supremacist now, affiliated with the American Freedom Party, which is openly white nationalist.