"Back when public service wasn't a lifetime career."
I beg your pardon...FDR died in office.
If his doesn't count as a "lifetime career," whose does?
He entered politics at age 28, was elected to the New York State Senate at 30, was appointed Assistant Secretary of the Navy at 31, and first ran for national office at 38. At 46, he became governor of New York, and at 50 he became president, in which office, as I said, he died at age 63, having won an unprecedented (and now illegal) fourth term in the White House.
He was the quintessential lifetime politician.