Those apocalyptic prophecies are a big part of it, yes. Many politicians are believers in those prophecies, and many more count on votes from those believers. There's also the whole "God's chosen people" stuff, and a lot of older people think Israel should be given a blank cheque due to WW2 stuff. And of course some of it comes from wealthy donors like Miriam Adelson, a desire to go overboard to distance themselves from the threat of being labelled an antisemite, a desire to paint themselves as more pro-Israel than the other party, etc.

It isn't much comfort that people who believe in apocalyptic prophecies have significant power in a country with a lot of nuclear weapons.