50% of the “Jewish Vote” are people who aren’t actually Jewish, but merely consider themsleves etnically Jewish.
If you look at shul-going (or even regular “temple” going), I am confident the numbers favor Republicans.
Same holds true for Catholics.
My guess is you’re right. I think most religious Jews are Republican and most nominal Jews are Democrats.
If the 2008 election was held in Israel, McCain would have been elected President, not the idiot we have now.