United States Attorney. Castro was not satisfied with his offer, as he felt he would be going backwards from being a Superior Court Judge, and rejected Elson while also stating that he wanted to be a U.S. Ambassador instead. Elson informed Senator Hayden of Castro's desire to be a U.S. Ambassador, and Hayden approached President Lyndon B. Johnson about the possibility of appointing Castro. At first, Johnson was opposed to appointing Castro due to the association of the surname Castro with that of Cuban President Fidel Castro, as well as Fidel's brother, Raúl Castro. Not wanting to potentially upset voters in the wake of the 1964 presidential election, Johnson requested that Castro change his last name, but he refused. Johnson relented, and selected Castro to be United States Ambassador to El Salvador in 1964. During his time as Ambassador to El Salvador, he was presented with the country's highest honor, the Order of José Matías Delgado. After four years as U.S. Ambassador to El Salvador, he was then appointed as United States Ambassador to Bolivia, and became known as the "Ambassador on Horseback," as Castro would ride into the countryside on horseback and greet the Bolivian citizens. While U.S. Ambassador to Bolivia, Castro's home was bombed twice by terrorists. He served in the position until the following year when Richard Nixon was elected president, and Castro was subsequently removed from office. Political career 1970 gubernatorial campaign After returning to Arizona and leaving his post as U.S. Ambassador to Bolivia, Castro was approached about the possibility of running for Governor of Arizona in the 1970 gubernatorial election. On June 18, 1970, Castro announced his bid for the Democratic nomination, challenging Phoenix auto dealer Jack Ross and Chandler Mayor George Nader. Castro held the announcement in Tucson, but no one showed up, believing that he had no chance of becoming the Democratic nominee. Despite this, Castro went on to win the Democratic nomination by a significant margin, and challenged incumbent governor Jack Williams in his bid for a third term. During the general election campaign, Republicans attacked Castro for supposedly favoring Mexican immigrants during his time as Pima County attorney, and that he had been an "adequate" judge, but not an "outstanding" one. Ultimately, however, the Republicans decided against attacking Castro's record out of fear that they would be castigated for attacking a minority, which Jack Williams' campaign manager stated that he