Letters from William P. Clements, Jr. to John Hill, 1978. Five open letters from William P. Clements, Jr. to the Honorable John Hill from August 11-September 8, 1978. Clements urges John Hill to join him in open debate on issues of binding referendums, voting on new or increased tax bills, a Constitutional amendment in Texas to ban income tax, voter referendums on tax increases, and Jimmy Carter.