I will be surprised if this happens. There may be a few Democrats from areas with significant Jewish populations who will object weakly, but for the most part the Left and the Democrats are becoming more and more anti-Israel and anti-Jewish.
Ignorant people the world over hate the Jews.
I don't know. If Carter has managed to get the mostly liberal Reform Jewish community up in arms against him, that could produce significant fallout for the Dems. I mean the guy is an ex-President who is all over TV.
Further, Jimmy Carter is a real malcontent. I mean the Democratic Party nominated him twice for President. So his way of saying "thank you" is to go out his way to screw up and weaken the Democratic nominee in 2004 and now 2008.