That's plausible, but I think it would mean that phone calls don't actually have much influence if someone with money is influencing the politician in the other

That's plausible, but I think it would mean that phone calls don't actually have much influence if someone with money is influencing the politician in the other direction. I'm willing to believe that phone calls actually don't have much influence, but I keep hearing from former staffers that they are influential. Maybe they say this because it influences their recommendations to the politician (which may or may not be heeded), but this would still leave the system open to abuse.