Obama won Florida by about 200,000 votes. Around 650,000 Jews in Florida, all ages. Very generously, half are voters and actually voted, a 15% or 20% shift wouldn’t have mattered. Fortunately GWB won the state in 2000, but a 1% shift would have mattered then, so it could be significant in some states, like Florida.
Especially if Pat Buchanan is running on a 3rd party ticket.