I know that churches may not post signs to support or oppose a candidate for election, but what about other ballot issues? Is it legal for a church to post a campaign sign advocating a "Yes" vote on the November 2012 Minnesota Marriage Amendment?
Section 501(c)(3) charities, including churches, are prohibited by the Tax Code from participating in election campaigns and can lose their tax-exempt status if they do so. (See Ready Reference Page: “IRS Issues New Guidance on Electioneering”) But they may lobby on legislation so long as it is not a substantial part of their activity. (See Ready Reference Page: “Lobbying Rules Create Opportunity for Charities”) The IRS considers a voter referendum such as this one seeking to amend the state constitution to be “legislation” so a lawn sign supporting one side of /the debate would be permitted.