he is doing the exact same thing that the Israeli government and corporate media have been doing when they call anyone who criticizes the Israeli government an antisemite.

I agree.

supermajorities of folks in all political parties support folks labeled as antisemitic, because we all understand that the antisemitic label is complete bullshit now

Antisemitism is still a thing - it just happens to be a thing that's perpetrated by those claiming Israel as 'the Jewish state' (and attributing their actions to those done by 'the jewish people') and by people who go along with that conflation. Supermajorities don't support antisemitism, they oppose Israeli apartheid. That just makes it all the easier for actual antisemites to cover under the same political rock and pretend that they're in the majority, while simultaneously leaning into the Jewish identity of the perpetrators of that genocide.