The Kennedys have always tended their family's legacy tenderly and brilliantly. Look no further than the Kennedy Library, the Kennedy Center and the Kennedy School of Government. Not to mention the notion of "Camelot," shrewdly dropped by Jackie Kennedy in a 1963 magazine interview. The rest wasn't history, but gauzy romanticizing.

It was in this tradition that Ted Kennedy endorsed Barack Obama last year, symbolically passing the Kennedy torch outside the family. The endorsement kept the Kennedys identified with the future and accented their historic support of civil rights. If a Kennedy doesn't ever again make it to the White House, the liberal lion was making a play for the next best thing — a Kennedy by proxy.

It worked. Not only did Kennedy's endorsement give Obama a boost in a tight nominating contest, it ensured he would be forevermore associated with the Kennedys. In a sign of how thoroughly liberal opinion-makers had taken the bait, MSNBC talk-show host Chris Matthews called Obama "the last [Kennedy] brother" within hours of Teddy's death.

Democratic leaders want to exploit this symbolic line of succession in the push for ObamaCare: The heir to the Kennedy dream champions Teddy's lifelong cause of universal health care as a final tribute to the lost liberal lion. But sentimentality is a poor rationale for reordering one-sixth of the economy. It'd be much more cost-effective to build for Kennedy the National Mall's most expensive monument ever than to pass a new $1 trillion entitlement in his honor.

It's a weak argument, in any case. The swing votes in Congress tend to represent conservative-leaning districts and states where Kennedy, as a liberal icon who worked tirelessly to expand government regardless of costs, represents the pitfalls of the bill rather than its attractions. This goes to a deeper lesson about Ted Kennedy that shouldn't be lost in all the effusions about his effectiveness within the Senate — his unadulterated liberal politics were an electoral loser at the national level.

From 1968 to 2008, only two Democrats were elected president, and both were Southerners who ran as moderates, Jimmy Carter and Bill Clinton. Kennedy, of course, unsuccessfully challenged Carter in the 1980 primaries for what he perceived as his lapses from liberal dogma. Clinton might have styled himself Kennedyesque in his youthful idealism, but after 1994 he hewed closely to the center.

Then came Obama, who slayed the establishment Democrat Hillary Clinton by motivating the party's base and energizing young voters with flights of uplifting rhetoric. It was everything Teddy Kennedy hadn't been able to do in 1980. Obama seemed set to fulfill an old Kennedy-inspired Democratic hope — that a liberal paladin would rise up who would be so irresistibly talented and glamorous he'd complete the shining work of the tragically foreshortened Camelot in an onrush of liberal reform.

This is a false hope Obama had best resist. It depends on myth. First, JFK himself was a pragmatist, not a left-wing crusader — cautious on civil rights, hawkish on the Cold War, willing to cut taxes to spur growth. Second, Obama's centrist-sounding general-election campaign owed more to Carter and Clinton than to Ted Kennedy. Third, legislative victories for liberalism since the Great Society have generally been incremental ones, many of them won — ironically enough — by Ted Kennedy.

Although Kennedy relentlessly plugged for a big-bang nationalization of health care, he learned to take what he could get. After the demise of HillaryCare, he adopted the much more modest S-Chip program to insure poor kids, passed in 1997. It has steadily grown until it now covers kids in families up to 300 percent of the poverty level and some adults. That's how a shrewd liberal slowly nationalizes health care.

Obama's ambitions — reflecting the Kennedys of myth rather than fact — make him reject such incrementalism. If Teddy Kennedy's death makes Obama even more insistent on his current path, the late Senate great will have bequeathed him a legacy of political poison.

Rich Lowry is a syndicated columnist. He can be reached by e-mail at: comments.lowry@nationalreview.com.