Right. That's what actually buys you the politician. Being able to promise "Pass this regulation for us and we'll make sure you are set up for life, since we know it's politically unfavorable"

the ~$2M just gets your foot in the door, that's it.

And also they can threaten to fund an opponent's PAC.

That's the real evil. Once a super PAC has enough money, they don't even have to spend it. The threat alone is enough to get most Congress people back in line.

Or primary you

Opponents run in primaries too, not just general elections.