California's Governor Ronald Reagan and Senator Thomas Kuchel are both Republicans, but the similarity ends there. They have been ideologically estranged and on opposite sides of party fights for years. Thus Reagan's election in 1966 seemed like a requiescat for Kuchel, who seeks his third full term next year. Of late, however, pressed by party leaders, the antagonists have been quietly learning to live and let live.
Détente has not come easily. Kuchel, 56, among the most liberal and independent of Republicans, is anathema to many of Reagan's conservative supporters. In 1962, Reagan...