Bill Clinton bashed President Bush in a speech delivered from the pulpit of a prominent Manhattan church on the Sunday before the Republican National Convention began. Yet, Americans United for Separation of Church and State does not view Clinton's pulpit-based diatribe a violation of tax laws. Ever since then-Sen. Lyndon Johnson (D.-Tex.) slipped a provision into a bill back in 1954, federal law has prohibited tax-exempt churches from engaging in partisan political speech. Every election season, Americans United files complaints against churches that it alleges have violated this law. The group also opposes the Houses of Worship Free Speech Restoration...