It's not that House Speaker Nancy Pelosi and other congressional leaders made any fatal legislative moves. Indeed, Pelosi had good reason to liken the landmark legislation to the passage of Medicare, if not Social Security.

Millions of Americans now without health insurance would receive coverage under the $1.2 trillion plan, and those with workplace-based insurance would be more assured they could keep their coverage.

Unfair insurance industry practices such as denying or dropping coverage due to medical condition finally would be banned.

In the boldest move, private insurers would see competition for the first time from a government-run health plan serving working-age Americans.

But as congressional action shifts to the Senate, the House plan clearly cannot serve as the only template for the bill that eventually reaches President Obama's desk. Primarily, that's because it's unaffordable in its present form despite bearing the title "Affordable Health Care for America Act."

Unfortunately, the House measure does little to rein in escalating health-care costs, and that, in the end, would harm the middle class and small businesses alike.

Although the nonpartisan Congressional Budget Office estimates that the measure would reduce federal deficits by about $104 billion over a decade, the House conveniently excluded $250 billion in estimated Medicare payments to doctors over the same decade.

At least, the House gets it right by paying for much of the plan through a tax on high-earning Americans, rather than the Senate's disadvantaging richer Northeastern states with a tax on health plans.

But the cost-containment measures fall short of what the Senate has proposed, accounting for some erosion in Democratic support during the close, 220-215 vote. For one, freshman Rep. John Adler (D., N.J.) said he voted against the plan over its cost.

So the Senate will have to impose its own reality test on cost - certainly, if Majority Leader Harry Reid hopes to hang on to the votes of conservative Democrats in his ranks. (The House hard-line stance limiting abortion coverage also could complicate Reid's hunt for 60 votes, since it's likely to be viewed as patently unfair to many low-income women.)

While Reid was being urged Sunday by the president to "take up the baton and bring this effort to the finish line," the Senate leader will need Obama's help in pushing for greater reform efforts to bend the cost curve. Only with real efficiencies - in addition to taxes and cuts in Medicare - will the nation be able to improve and help pay for expanded coverage.

One of the surest means to tamp down costs is to implement a Medicare-style health plan, as the House proposed. So even though the so-called public option is a deal-killer for Republicans and a few conservative Democrats and independents like Sen. Joseph I. Lieberman of Connecticut, the Senate must find a way to craft a compromise that preserves this key reform measure.