David Rothkopf answers the question here by asking:
“What makes the idea of this particular lobby more sinister than all those farmers or Cubans or African-Americans or gays or union members or Arabs or Taiwanese or Christians?”
Elsewhere, Yoram Ettinger adds his thoughts on the matter:
“Iran’s nuclear threat is a symptom of endemic Middle East violent unpredictability and Muslim hostility toward Western democracies. It calls for an upgraded US-Israel win-win relationship, which requires a strong Israel as a national security producer. A weak Israel, pushed into a nine-15 mile sliver along the Mediterranean, pressured to concede the mountain ridges of Judea, Samaria and the Golan Heights, relying on foreign troops and guarantees, would become a national security consumer. It would be a burden rather than an asset to the US in a bad neighborhood, which is crucial for vital US interests. “