But I think the issue here is whether a church supporting a nonpartisan issue such as a gay-marriage ban is running afoul of this rule, or whether the rule only covers political activity of a partisan sort (supporting a Republican candidate over a Democratic candidate, for example). Perhaps FR lawyers might chime in here.
The church I've been attending lately, one of the largest mega-churches in the country (#6, I think), reminds its congregants to support the constitutional amendment to ban gay marriage at every service. If this somehow cost them their tax-exempt status, that would be a train wreck -- they receive six or seven hundred thousand dollars a week in offerings.
Hey Jo-Jo, here is an explaination:
http://www2.state.mt.us/cpp/css/1abouttheagency/missionhistory.asp