A task force of the American Bar Association sensibly recommended last year that the 20 percent rule be eliminated, which would require far more people to register as lobbyists, and subject them to ethics and disclosure requirements. (The Center for Responsive Politics found that more than 3,000 lobbyists simply “de-registered” after Congress imposed new reporting requirements for lobbyists in 2007.) Of course, many prominent influence-peddlers do not actually meet with lawmakers or federal officials themselves. They provide “strategic advice” on how to navigate Washington and whom to see, while other members of their firms do the face-to-face lobbying work. (This is how Mr. Gingrich made most of his millions.)

With a better lobbying law, the work of these consultants would also be disclosed. Whenever a lobbying contact is made with a lawmaker or bureaucrat for a client, a form should be filed showing all the people who worked for the client, how much they are paid, and what work they did regarding a law, an earmark, or a regulation.

Disclosure, however, does not stanch the pipeline of money from the lobby industry that remains out of control. On Tuesday, President Obama proposed an important reform that would prohibit lobbyists from fund-raising for federal candidates they had lobbied in the previous two years and would also prohibit fund-raisers from becoming lobbyists during the same period. There should also be lower dollar limits on how much lobbyists can contribute in total to federal candidates, party committees and political action committees.

President Obama has said he will not accept contributions from lobbyists, but at least 15 of his biggest fund-raisers work in lobby shops and are unregistered. Meanwhile, the Republican candidates have taken in hundreds of thousands of dollars from lobbyists. And there are no limits on donations to unregulated “super PACs”.

Congress has shown little interest in tightening these requirements, in part because lawmakers don’t want to close off a lucrative career in lobbying after they leave office. More than 400 former lawmakers have become lobbyists or consultants in the last decade.