AUSTIN — A new Texas law provides public school teachers with immunity from prosecution for violating the U.S. Constitution’s First Amendment clause calling for separation of church and state, Texas Education Commissioner Mike Morath testified Monday in front of state lawmakers. The revelation came during a tense meeting of the Texas House Committee on Public Education, which met to conduct hearings on new school vouchers in addition to new lesson plans and programs for the state’s public schools. During the hearing, State Rep. James Talarico, an Austin-area Democrat, grilled Morarth on new educational materials revised under House Bill 1605.