Like most older Baby Boomers, I vividly remember John F. Kennedy’s assassination on November 22, 1963. So on the 56th anniversary of that tragedy, I wrote about his legacy at New York.

JFK’s truncated presidential tenure and youth (he was 46 when he died) has complicated his legacy through a combination of what-ifs and revisionist arguments, not to mention the many political figures, including multiple representatives of his large family, who claimed to be carrying the banner he dropped when he was felled in Dallas. A cautious and sometimes conservative politician who was a zealous cold warrior, Kennedy became for many — particularly the African-Americans who benefited from the civil-rights legislation his successor Lyndon Johnson pushed through Congress as a memorial to him — a symbol of 20-century liberalism. In no small part that was because his brothers Bobby and Teddy embraced the full-throated progressivism that many thought Jack was evolving toward when his life was cut short.

He was more properly a transitional figure. In his famous inaugural speech he pointed to himself as the representative of “a new generation of Americans — born in this century.” His political career and presidency triggered the beginning of a major realignment of the two major political parties, even as, in his own election in 1960, he hung onto just enough of the old southern segregationist wing of his party to narrowly beat Richard Nixon, benefiting from an expanded urban ethnic constituency (he won an estimated 80 percent of the Catholic vote, as the first Catholic major-party nominee since Al Smith) and an enhanced Democratic advantage among the African-Americans who would soon gain growing electoral clout as Jim Crow came to an end.

Civil rights wasn’t the only area in which JFK represented a cautious leftward turn in his party. In 1960 he campaigned avidly for what became the Medicare program after his death, as Julian Zelizer recalls:

“Labor leaders cheered when Massachusetts Senator John Kennedy announced his support for Medicare during his 1960 Presidential campaign against Richard Nixon. Kennedy was no radical, but he believed that health care was one area where the government needed to have an expanded role. Kennedy saw the revised health-care bill as attractive in principle, as well as fiscally responsible, because workers would pay for the benefits that they would eventually receive. On August 14, 1960, Kennedy visited Hyde Park to celebrate, with Eleanor Roosevelt, the twenty-fifth anniversary of Social Security, and he used the occasion to promote Medicare. The program was desperately needed in ‘every city and town, every hospital and clinic, every neighborhood and rest home in America—wherever our older citizens live out their lives in want and despair under the shadow of illness,’ the candidate said.”

As president, JFK was also planning an anti-poverty initiative that later blossomed as LBJ’s “War on Poverty.” An endless amount of speculation has surrounded the question of Kennedy’s responsibility for the Vietnam War, and what would have happened to the U.S. anti-communist effort in southeast Asia had he lived out his term (and perhaps won a second term). Probably the best guess is that he would have escalated U.S. involvement in Vietnam in the short term, but would not have exhibited the personal stubbornness that led Johnson to keep expanding the war even when it was becoming obvious it couldn’t be “won.” Remembered so often as an “idealist,” Kennedy was nothing if not pragmatic.

It’s probably best not to credit or blame JFK for the political dynasty his family created after his death; that was more the work of his father, who pushed all his sons toward high political office. After two subsequent Kennedy presidential campaigns (one ended by RFK’s assassination in 1968, the other by Ted Kennedy’s loss to Jimmy Carter in 1980), the dynasty gradually wound down, and at this point JFK’s grand-nephew Joseph P. Kennedy III, a U.S. House member from Massachusetts, is its chief scion. This latest Kennedy pol is now challenging incumbent Democrat senator Ed Markey next year, seeking to renew a tradition whereby the Bay State was represented in the Senate by a Kennedy from 1952 until Ted’s death in 2009. In an interesting echo of JFK’s inaugural address 58 years ago, the 38-year-old Joe Kennedy is running as the candidate of generational change against the 73-year-old Markey: “This is the fight of our lives, the fight of my generation — and I’m all in.”

And thus the family business continues.