Israel/Palestine

First, there's nothing wrong with a group of like minded people advocating for common interests and petitioning the government. It's the basis for our First Amendment, and extensively used by Democratic and liberal groups like NARAL and various environmental advocacy groups.

Democrats and liberals also have our own very active Super PACs supporting our party and political interests.

http://sunlightfoundation.com/blog/2014/09/22/liberals-still-top-list-of-largest-super-pac-donors/
https://ballotpedia.org/Super_PAC
https://en.wikipedia.org/wiki/NARAL_Pro-Choice_America

These types of groups are only supposed to represent their members. The "People" can join and contribute (or not) to any group they like, and many groups are indeed bipartisan.

In fact, AIPAC is one of the largest and most bipartisan political groups in the USA, as is readily evident from their active list of speakers and supporters.

Your complaint is essentially that AIPAC doesn't represent your opinions, and therefore is somehow less legitimate. As many polls in the USA readily indicate, your ideas about the I/P dispute and its potential resolution are a distinct minority view of "The People" of the United States.