Lieberman ran unsuccessfully for the U.S. House in 1980, was elected state attorney general in 1982 and 1986, and in 1988, with the help of conservative icon William F. Buckley, upset liberal Republican Sen. Lowell Weicker.
Lieberman's strong support of military action in the Persian Gulf in 1991 and in Iraq in 2003 and after enraged many Democrats, and he was beaten in the Democratic primary in 2006. He turned around and ran as an independent and, with no serious Republican nominee, was elected to a fourth term.
Evidently he could see no way forward in 2012. As he said, "The politics of President Kennedy -- service to country, support of civil rights and social justice, pro-growth economic and tax policies, and a strong national defense -- are still my politics, and they don't fit neatly into today's partisan political boxes anymore."
That analysis stands up to scrutiny. "Let every nation know, whether it wishes us well or ill," Kennedy said 50 years and four days ago, "that we shall pay any price, bear any burden, meet any hardship, support any friend, oppose any foe, in order to assure the survival and the success of liberty."
In fulfilling that promise, Kennedy dispatched American troops to Vietnam, with a tragic outcome. Four years ago, many Americans expected, and at least a few relished, a similar outcome for our enterprise in Iraq.
But George W. Bush doubled down with his surge strategy, and Lieberman provided critical support for it in the Senate, with far happier results.
John Kennedy's inaugural, like Sargent Shriver's institution-building, does not fit the partisan template of today's Democratic Party. Kennedy's words come closer to resembling those uttered by another American president, who delivered his first inaugural from the West Front of the Capitol 30 years ago last Thursday, Ronald Reagan.
As Shriver's death and Lieberman's retirement suggest, Kennedy's heritage is now national and historic, not contemporary and partisan.