Democrats are today celebrating a victory that has revitalised the party, revived a faltering presidency, and set in motion the biggest changes to America's system of healthcare since the heady days of Lyndon Johnson's “Great Society” programmes of the 1960s.
The 219-212 vote by which the House of Representatives approved the Senate's version of healthcare reform late on Sunday night is of course anything but the end of the battle.
Republicans who unanimously opposed the legislation vow to continue their fight, and the chief legal officers of a dozen Republican-governed states threaten to block it on constitutional grounds, as a violation of States' rights.
More immediately, the Senate must pass a separate package of fixes to the measure enacted by the House — anything but a given, even under the budget-related “reconciliation” process that will be used, whereby Democrats require only a simple majority of 51.
Republican leaders again served notice they will throw up every possible procedural obstacle, as John McCain, the party's defeated 2008 presidential nominee, declared that Democrats had not heard the last of the argument.
But, for the moment, there was no hiding the delight of Democrats at the achievement of a goal that has eluded every President since Harry Truman, of bringing guaranteed health insurance to virtually all Americans.
Whatever happens now in the Senate, Mr Obama will be signing a bill within days.
In a deliberately symbolic gesture, the gavel used to close debate and announce the result was the same one used in 1965 when Congress passed the Medicare and Medicaid reforms, providing coverage for the elderly and the poor.
Afterwards, an exultant Mr Obama acknowledged that the $940bn (£623bn) measure will not correct every failing of the vastly expensive and inefficient US health system. But “it's a victory for common sense. It moves us decisively in the right direction. This is what change looks like.”
The victory sealed an extraordinary turnaround since January 19, when the shock Republican capture of the late Edward Kennedy's seat in Massachusetts cost Democrats their 60-vote filibuster-proof majority in the Senate. At that moment, reform hopes seemed dead.
But, prodded by Nancy Pelosi, the House Speaker, Mr Obama resolved to press on regardless, with a new strategy involving only a simple majority in the Senate, where Democrats and their allies still hold 59 seats. Having decided to stake all on victory, a galvanised President produced the passion and rhetoric not seen since the campaign trail of 2008.
On Wall Street, shares in insurance and hospital companies rose at the opening, amid the realisation that many of the bill's most important provisions will not take effect until 2014, and its ultimate impact is unclear.
Some 32 million Americans will be covered, extending insurance to 95% of the population. In future almost everyone without insurance will be required to buy it, with the aid of tax credits and other subsidies for families earning less than $88,000 (£58,000). If they do not, they will face fines.
In return for all the new customers, insurers will be barred from such practices as refusing coverage to people with pre-existing conditions, and withdrawing it when people need it most.