This is my understanding as well. The majority of the money between politicians and business entities or wealthy individuals moves out of band and out of sight.

This is my understanding as well. The majority of the money between politicians and business entities or wealthy individuals moves out of band and out of sight. Lobbyists are the glue that makes those deals happen. So the $3.5M went to pay the lobbyists to negotiate the much bigger deals that ultimately sway the opinions of the politicians.