The First Amendment provision defining the separation of church and state stands as one of this country’s most valuable contributions to civilization. It allows everyone to worship; it forces no one to worship; it entertains diversity of faith; and it keeps the government to the secular business of governing for the welfare of its people. It is genius in a few simple phrases that limits the power of Congress in making laws respecting speech, faith, and other expressions of thought. The success of the doctrine has served as a model for developing countries as they sought ways to govern effectively in spite of deep religious divisions in their societies.
There is no constitutional provision that limits the expression of political views in religious services or within any of a church’s activities. That would contradict the free exercise clause. But, alas, there is the problem of taxation.
Churches that express political views or endorse candidates become subject to the federal income tax. And their donors, cannot deduct their gifts from taxable income. The rationale for the deduction recognizes the spiritual nature of the church and extends the favor of immunity from taxation only that far but not so far as any interest the church may express in influencing policy or in choosing the government. And, true or not, churches behave as though their institutional lives depended on being exempt from paying taxes and eligible for having their donors receive deductions.