The first reason for lobbying is classic interest-group politics:
Well-financed, well-organized lobbying groups strongly oppose major bills..
Often no powerful grass-roots group are devoted to merits of certain issues.
Groups representing interests of the wealthy have enlisted effective lobbyists.
Former members of Congress are most effective lobbyist.
Groups representing the wealthy enlist most effective lobbyists in Washington: former members of Congress.
Most Lobbying campaigns are able to succeed
Even when they are trying to persuade elected officials to defy public opinion
Fewer tax increases leave less money for health care, schools & clean energy,
Leads to contentious intra-party debates over parts of a plan should be cut.
Outside groups like super PACs are required to disclose their donors.
Others are not. Non-disclosing organizations are dark money groups.
Most effective lobbyists in Washington: former members of Congress.
The obvious reason for lobbying success is campaign donations & is no doubt part of the answer.
But there is also a more subtle dynamic at work to accomplish the end legislation after lobbying,
Dirty or Dark Money should be reported & published for every bill going through Congress,