The issue has nothing to do with US Elections. That is a MYTH. Some in the punditocracy think so, but they also believe in magic bullets. Sorry, but Harry Potter is a children's story, no matter how well written. The last cakewalk the US got sold was Iraq. And the magic bullet was "shock and awe." Not that US concerns matter to Netanyahu.
Netanyahu: Most of Americans see eye to eye with Israel on dangers of Iran deal (Haaretz)
from the article: Barak will have to pass an attack on Iran through a reluctant U.S.