Representation by lobbyists unwanted, US

The modern American way to lobby for an anti competitive merger is to hire lobbyists who are tied into networks of support for major politicians.

Each time these lobbyists go to work, their goal is harmful to the public interest. We should change our laws so that there are no such lobbyists — but how to do that? I tend to think that blocking large anonymous campaign donations, and blocking all campaign contributions from corporations, would tend to correct this problem as a side effect of correcting the problem of legalized bribery.