The IRS' decision circumvents a decades-old ban on political activity by tax-exempt nonprofits.  The Johnson Amendment of the U.S. tax code, which bans all 501(c)(3) nonprofits from endorsing or opposing political opponents,

The rule was introduced by former President Lyndon B. Johnson in 1954 when he was serving as the U.S. Senate majority leader. It banned all tax-exempt organizations like churches and charities from “directly or indirectly” participating in politics, specifically in endorsement or opposition of candidates.