The history of Kennedys’ meddling with Senate seats goes back even further:
“...Joseph Kennedy wanted Ted to fill John’s Senate seat, but because the Constitution required that all U.S. senators be at least 30 years of age, Ted would not be eligible to hold that office until February 22, 1962. On Joseph Kennedys insistence, President-elect John Kennedy asked Massachusetts Governor Foster Furcolo to appoint Benjamin A. Smith II, a Kennedy family friend, to fill Johns old Senate seat until 1962, at which time he would be expected to step down and permit Ted Kennedy to run for the office in a special election; Furcolo complied, as did Smith.”
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