Photo: Al Drago/Getty Images When Robert F. Kennedy Jr. threw the Centers for Disease Control and Prevention into turmoil last month, after his subordinates reportedly refused to carry out his regressive vaccine policy, it was a perfect distillation of the fears held by Kennedy’s strongest opponents and critics. But while Senator Bill Cassidy of Louisiana — the Republican physician whose vote was key to Kennedy’s confirmation — appeared to express concern over the personnel changes at the CDC,