Pastors' Web Electioneering Attracts U.S. Reviews of Tax Exemptions

There was a time when a minister like James David Manning could stand in the pulpit of his little church on 123rd Street in Harlem and say pretty much anything he liked about a presidential candidate. Beyond his community of devoted parishioners, who was to know? But when Pastor Manning, who is black, posted an angry sermon in February on the Web site of his church, the Atlah World Ministries, denouncing Senator Barack Obama as a "pimp" and Mr. Obama's mother as a "trashy white woman," his preaching spread like a virus on YouTube, earning lavish attention on right-wing talk shows — and two weeks ago, the less-welcome attention of a watchdog group, which filed a formal complaint with the Internal Revenue Service. The I.R.S., which can revoke the tax exemptions of churches that express support or opposition to candidates for public office, has declined to say whether it is reviewing Mr. Manning's case. But in the past year, the agency has undertaken its first serious look at the digitized church world that his sermon represents, issuing a set of new guidelines that bar electioneering on the Web. Both partisan-minded religious groups and those that police the boundaries between church and state say the implications of that new scrutiny are great.