Earlier quoted context omitted.
If it was banned, it would still happen, but not in the public eye. A relative of a friend was a politician. He used lobbyists indirectly to work on issues. Say he needed help understanding a school textbook issue. He would call up his oil lobbyist, whose job it was to make him happy. It was definitely not his job to piss him off. He would quickly get a report on the textbook issue, probably written by the expert in…
The lobbyist then gets to choose an expert which represents the lobbyists worldview. This is what he is getting paid to do.
But the oil lobbyist wouldn't have a horse in the game for school textbooks. He would play fair in the hope that the politician would "play fair" on future oil issues.
It's a wierd sort of politician problem solving, making do with the resources you have.