Do you feel that way about all organizations, like the ACLU?
Sure. Perhaps I should clarify though. The reason I'm upset about the NRA in this instance is because the PA legislature changed the law so that these cities can be sued even if someone hasn't shown that the law has actually hurt them. Prior to this there had to be some ground to the lawsuit. Not anymore. So in a scenario like that I would also be against a group like the ACLU. On the other hand, I believe that groups like the ACLU, and probably NRA also, have represented or given support to people who can make a case that a law has caused them some damage. In those cases I'm not against it.
I'd be lying if I said that I'd have exactly the same feeling in any and all cases where an organization sues or joins a lawsuit, but in a case like this it isn't simply because they are the NRA.