Mat Staver is the former dean of Liberty University’s law school, a snow-haired 67-year-old who has argued two cases before the Supreme Court. For a week last month, he acted as much like an old-time blues musician.

The founder of Liberty Counsel, an Orlando, Florida-based Christian legal group, Staver hit the road to meet evangelical pastors and explain why they should oppose a Nov. 5 referendum that would gut Florida’s restrictions on abortion after six weeks of pregnancy and enshrine a qualified right to abortion until birth.