Not even the biggest Jewish 'Rat would even dream of a 90% number. In 2008, the 78% O reputedly got was very likely an overestimate due to poor sampling technique in polling. The real number was probably somewhere in the 60s.
In 2012, look for Obama's percentage of the Jewish vote to be somewhere between 50 and 60%.
There is no bloc Jewish vote anymore, with the American Jewish community more diverse economically, geographically, and religiously. It's not like the bloc vote for the 'Rats by blacks.
I heard a reporter earlier this week on IIRC, the John Batchelor show, talking about how anticipated fundraising for Obama ‘12 is way below expectations. I would suspect that has much to do with the traditionally big buck Jewish donors sitting tight, at least for now.
What did he really gain by his bigoted anti Israel stance?