In his 1995 autobiography, "In the Arena", written after he became a conservative Republican, Heston wrote that while driving back from the set of "The War Lord", he saw a "Barry Goldwater for President" billboard with his campaign slogan "In Your Heart You Know He's Right" and thought to himself, "Son of a bitch, he right." Heston later said that his support for Goldwater was the event that helped turn him against gun control laws. Following the assassination of Senator Robert F. Kennedy in 1968, Heston, Gregory Peck, Kirk Douglas, and James Stewart issued a statement in support of President Johnson's Gun Control Act of 1968. The Johnson White House had solicited Heston's support. He endorsed Hubert Humphrey in the 1968 Presidential election.