Two years ago, the Senate rejected an attempt to regulate "astroturf," professional political agitation aimed at stimulating (or simulating) grassroots activity. Recently, that measure's supporters have been saying, "I told you so," citing the debate over who is behind boisterous criticism of President Obama's health care agenda at congressional town hall meetings.

But if the problem is that special interests with deep pockets tend to dominate public policy debates, stricter limits on political speech will only make things worse. The pros are in a much better position to comply with complicated, demanding registration and reporting requirements, which expose ordinary citizens to legal risk and discourage them from speaking their minds.

Last week Public Citizen lobbyist Craig Holman, whose group supported the astroturf provision rejected by the Senate in 2007, complained to The Hill that the lack of disclosure about business groups' instigation of protests against health care reform makes it hard to know what's really going on. "This goes below the radar," he said. "We don't know who is behind it or who pays for it. We don't know how much of it is happening."

The difficulty is that Holman's right to know conflicts with other people's constitutional right to speak.

The regulations he favored would have required "grassroots lobbying firms" to register with the government and file quarterly reports on their activities. But the definition of such firms was broad enough to cover advocacy groups such as the National Rifle Association, the National Right to Life Committee and the American Civil Liberties Union. Continued...