There wasn't really a "during" the holocaust for the ROW
only the results of the holocaust. There were rumors but no one had any idea of the horrific extent of the slaughter.
Antisemitism and racism in general were more accepted in the US, (In the South Jim Crow laws were undistinguishable from the laws in 30s Germany regarding Jews) but Hitler was universally hated and few people were looking the other way on anything he did in this country.
What you are referring to might be somewhat true for some European countries where antisemitism was rampant. The Germans were not the only country that hated Jews, but their "final solution" was not popular anywhere