Joe and Rose and Jack and . . . Gloria : Television: ABC’s six-hour ‘Kennedys’ is the best drama yet on America’s star-crossed political family.

The Kennedys have had an enduring legacy not only in United States politics but also in the media.

Venues have ranged from the nightly news to supermarket tabloids. Plus biography after biography has surfaced in publishing and television, giving the nation’s most storied, star-crossed family a sustaining presence and mystique unmatched by any other lineage in contemporary American life.

The roots of this phenomenon surface in “The Kennedys of Massachusetts,” a superior, six-hour drama airing at 9 p.m. Sunday, Monday and Wednesday on ABC (Channels 7, 3, 10 and 42).

This extended Kennedy roots piece is TV’s best yet on the family, a finely acted, meticulously mounted, historically grounded, sometimes-outrageous, well-worth-your-time odyssey of politics and social behavior based on Doris Kearns Goodwin’s esteemed nonfiction book “The Fitzgeralds and the Kennedys.”

The Kennedys inevitably polarize public opinion. Love them or hate them, however, there’s no denying their impact on the nation or our continuing fascination with them.

The family’s story begins here in 1906 with Rose Kennedy’s father, John (Honey Fitz) Fitzgerald, as Boston mayor, and ends 55 years later with John Fitzgerald Kennedy’s inauguration as President.

We see the courtship and marriage of Rose (Annette O’Toole) and Joseph P. Kennedy (William Petersen) and how the family influences that shaped them will echo through the years and in turn shape the lives of their children.

We see Joe overcoming social rejection at Harvard and anti-Irish Catholic prejudices elsewhere to embark on a successful business career. We see him as a “B” movie mogul in Hollywood in the 1920s, which results in a bi-coastal marriage. Rose has babies, Joe has affairs, including a long, steamy one with Gloria Swanson.

The portrait of Rose is one of strength and stoicism.

The portrait of Joe has clashing colors, however. Here is a man who loves and is beloved by his family yet cheats on his wife and shapes his eldest son--”He’s presidential timber,” he boasts about family favorite Joe Jr.--to fit his own emotional needs and political ambitions. Here is a man who misses his father’s funeral to stay in Hollywood with Swanson. Even worse, here is a man who arranges, although with good intentions, for his retarded, increasingly violent daughter Rosemary to have a lobotomy (which goes wrong and renders her mindless and requires her to be institutionalized), without telling his wife.

William Hanley’s script brings in other interesting facets, including the rivalry between the family’s golden boy, Joe Jr., and seemingly carefree Jack, and also Rose’s steely, enraged opposition to the marriage of her oldest daughter, Kathleen, to a Protestant.

The story is never more interesting, however, than when depicting Joe Sr.’s outspokenly rigid isolationism while ambassador to England as war clouds hover over Europe. And director Lamont Johnson is never better than in mounting a simply grand scene showing the new ambassador and his wife being received by the king. Or later when depicting Joe Jr.’s funeral after his death as a Navy pilot in World War II, which thereupon pushes Jack to the forefront of his father’s political ambitions.

Petersen makes a very credible Joe Sr., capturing some of the ambiguities of a man who, indirectly, had a significant impact on contemporary U.S. politics and social history. It’s O’Toole, however, who shines brightest here with a performance as a proud Irish Rose that is at once commanding and subtle, one threaded by nuances that reflect the joy and anguish of being the matriarch of a family that experiences such soaring highs and gloomy depths.

In smaller roles, meanwhile, Charles Durning is wonderfully raw and vulgar as the scandal-tainted Boston politician John (Honey Fitz) Fitzgerald, and Madolyn Smith Osborne is a memorable Gloria Swanson.

This is very good work. Despite its length, however, what’s curiously missing in “The Kennedys of Massachusetts” is glue and depth, something to better fuse all these interesting episodes of family life into an even more revealing narrative that’s as deeply illuminating as it is compelling.

In addition, the story goes a little titillatingly hot and heavy on Joe Sr.’s Swanson affair (we see him in bed with her, but never with the wife who bore him nine children), and a little light on such details as Rose’s reaction upon learning of Rosemary’s lobotomy. This incredible incident is left hanging.

Author Goodwin said recently that in researching her book, she was told by Rose that Rose never visited Rosemary in the institution and thus didn’t learn of the lobotomy until years later--beyond the time frame covered by the book and TV adaptation.

Is that really believable? The Kennedy mystique continues.