You make my point. K Street is full of lobbyists from many different organizations. Teachers, gun owners, veterans, senior citizens, family groups, ethnic, racial, and nationalities, other nations, environmental groups, animal rights, business and trade organizations, unions, etc..........
A member of Congress has lobbyists from all sides of an issue bending his ear. Which one does he side with? It depends on his personal views, his district make-up, and many other factors.
Some of the most powerful lobbyists cannot even give campaign contributions because they are non-profit. A prime example is AARP--they are powerful because of their large membership that votes regularly.
I don't think I am naive about this. I think it is naive to think a member of Congress votes with the organization that gave him the most campaign contributions or that lobbyists only represent one side of an issue. A member does not vote pro-union because unions gave him money; unions gave him money because he voted pro-union. And lobbying and campaign contributions are two different tactics.
Without lobbyists members would not know very much about most legislation or how it will affect their districts. They represent the people through 4,000 different organized groups. An organization that gives campaign contributions to a member to vote a certain way is wasting his time if that will hurt the constituents of his district. Members often get contributions from both (several) sides of an issue. Which one influenced him (if any)?