Lobbying is mix of politics and public relations. Lobbyists hired by trade groups, special interests, to achieve goals in legislature, congress. Number of registered lobbyists in Washington, DC, has grown from 3,400 in 1976 to nearly 10,000 today. Probably another 20,000 lobby without being registered. Lobbyists, pro and con.
Lobbyists provide information.
But it's information with a bias, intended to sway opinion. Legislators often don't know much about issues until they hear from lobbyists. Lobbyists and donations. Lobbyists set the stage for campaign financing. Reelection campaigns are so expensive, politicians start raising money as soon they take office.