[ktRolster]

That kind of money gives the donor access.....that means the donor can talk to the politician, and present their side of the story (as convincingly as possible).

The politician will feel that she maintains neutrality, and is making decisions for herself (not influenced by money), but since she has only heard one side of the story, she is likely to choose in that direction.

Similarly, if someone says to you, "hey, I have a problem, can you help me?" then you will probably help them if it's not too much trouble. Politicians are the same, except it costs $400k to be able to tell them that. And then the politician feels good that they have helped someone.