The proposed changes, which were unveiled in late November, would classify much of the day-to-day activity of 501(c)(4) social-welfare groups, including voter education and registration, as political, thereby endangering their tax-exempt status. They would also prohibit public communication 60 days before a general election or 30 days before a primary election that identifies a political candidate — that is, nearly every advertisement aired by groups such as the conservative Americans for Prosperity or the liberal League of Conservation Voters — during the period when they are most effective.

The proposed regulations have a host of left-leaning groups worried that the 501(c)(4) rules could serve as a template for regulations governing 501(c)(5) nonprofits (unions) and 501(c)(6) groups (trade associations), and they are speaking out. Service Employees International Union associate general counsel John Sullivan told the Washington Post that the proposed rules “would be totally inappropriate for unions” because they are “broadly phrased and categorical,” and that they would “seriously affect [unions’] ability to function.”

The American Civil Liberties Union, meanwhile, submitted a 26-page comment to IRS commissioner John Koskinen slamming the proposed regulations. “Social welfare organizations praise or criticize candidates for public office on the issues and they should be able to do so freely, without fear of losing or being denied tax-exempt status, even if doing so could influence a citizen’s vote,” the group wrote, calling such advocacy “the heart of our representative democracy.” The ACLU argued that, if the advocacy of social-welfare groups influences voting, it does so only by “promoting an informed citizenry.”