One of the biggest changes in lobbying in recent years has come with the appearance of public interest lobbies. They are so named because they claim to speak for the public, not for business interests. Instead of working for big industry or a labor union, public interest lobbyists usually work for a group of citizens.

There are hundreds of such groups in Washington and in state capitals. One of the best known is Common Cause.

When Common Cause was founded in 1970 by former Secretary of Health, Education, and Welfare John Gardner, many politicians laughed. They had seen "good government" groups come and go. "High ideals but no staying power," was the verdict.

But Common Cause had staying power. It has lost some battles, like the one against the Alaskan pipeline. But it backed the vote for 18-year-olds, and nudged Congress toward selecting committee chairpersons by merit rather than the seniority system. Today, Common Cause is a solid force in Washington.

So is another organization of its kind, Ralph Nader's Public Citizen lobby. Groups like these have hundreds of thousands of members today. And because they are backed by enthusiastic volunteers, they can generate large numbers of letters and telegrams to legislators and others in government.

Adapted from Politics & People, Scholastic Inc.