How many Jews are 40%?
Well, Jews make up a little over 2% of the U.S. population, more or less. So 40% would, assuming the vote turnout is nearly the same among Jews and non-Jews, be about 1% of the voting population.
A typical Republican gets about 20-30% of the Jewish vote. So 40% would be a swing of about 1/4 to 1/2 of a percentage point... not much, although in Florida, that might make a difference. A lot of Jews are in New York City, where the electoral votes are locked into the Dems anyway.