Non-Jews can absolutely care about antisemitism and defend Jews and even be absolutely horrified and outraged over the testimony of the three college presidents.
Stefanik is absolutely not one of those non-Jews who care about antisemitism.
I’m sick to death of the “The Real Antisemites” discourse, where one side’s antisemitism, (in this case, the antisemitism from the right and Stefanik’s complete refusal to call any of it out while stomping her feet in outrage when the antisemitism is politically advantageous), is either downplayed or completely dismissed in favor of the politically advantageous kind.
Either call out antisemitism whereever it occurs and quit giving people a pass just because they share your politics, or shut the fuck up.