Just as if he were really in a contest, Presidential Candidate Adolfo López Mateos rolled through Mexico City this week at the head of a giant parade of gaily decorated floats and charros (cowboys) on prancing horses. As they have since 1946, Mexicans will go to the polls next week andbarring an upset more sensational than Harry Truman'select the candidate of the Party of Revolutionary Institutions (P.R.I.) to a six-year term.
Former Labor Minister López Mateos, 48, was hand-picked for his job by the inner circle of P.R.I. politicians, and he has used the campaign mostly as a chance to...