Cleaver was later baptized into The Church of Jesus Christ of Latter-day Saints (LDS Church) on December 11, 1983, periodically attended regular services, lectured by invitation at LDS gatherings, and was a member of the church in good standing at the time of his death in 1998.
By the 1980s, Cleaver had become a conservative Republican. He appeared at various Republican events and spoke at a California Republican State Central Committee meeting regarding his political transformation. In 1984, he ran for election to the Berkeley City Council but lost. Undaunted, he promoted his candidacy in the Republican Party primary for the1986 Senate race but was again defeated.