This is one of the few times when the correct word is “effect”, not “affect”. “Affect (v.)” means to alter, or have an impact on. “Effect (v.)” means to produce, and to create an effect (n.) of.
Change is to alter something, not to create/produce something.
I wrote it as wanting to affect how Congress does things, to change what Congress does, to have an impact on Congress, which is what lobbying does.
I stand by my usage of the word affect, over effect.