Way back in the aughts, Move On had a contest in which anyone could submit a video for an ad. I don't even remember what it was for. One random person submitted an ad that was deemed to be anti-Semitic. If I remember correctly - and I might not! - it wasn't even really anti-Semitic, it just made some inappropriate Nazi comparisons (one can understand that facile and incorrect Nazi comparisons aren't really acceptable while still seeing that antisemitism wasn't the likely intent). This was enough for Democrats to denounce Move On and their evil ways, with the media basically demanding it. I might be mis-remembering how bad the ad was, but the real point is that it was submitted by a random person in a contest open to everyone, not the recipient of the Move On Oscar or anything.
Now Trump supporters are filled with neo-Nazis, white supremacists, white nationalists, the alt-right, or whatever they're calling themselves this week. You don't have to go nutpicking to find blatant and outspoken antisemitism. Not a lot of denouncing going on.
Will Republicans lose the Jewish vote? You know, the one they never win anyway?