Senator Olympia Snowe arrived for Tuesday’s Senate Finance Committee meeting on Capitol Hill with her mind made up. She had decided whether or not to grant President Obama’s fervent wish and back his favourite health reform bill.

We knew this because she told the crush of photographers waiting for her. The only thing we didn’t know was what she had decided, and for three hours she wouldn’t say. For three hours, everyone waited – Mr Obama, the insurance companies, Wall Street, the insured, the uninsured and the merely fascinated.

What was fascinating was the spectacle of American democracy at the sharp end, where the fate of Mr Obama’s flagship domestic initiative, and the trillion or so dollars it will cost, came down to precisely one woman and one vote. Put like that it sounded like democracy at its purest. In reality it was democracy at its strangest.

There is a Democrat in the White House. There are Democratic majorities in both houses of Congress. All have signed up to the goal of ending America’s status as the only advanced economy without universal healthcare. So has most of the public: even after a summer of vintage mischief-making by the hard right, 65 per cent of Americans say they like the idea of a state-run health insurance option.

Almost certainly, they will not get it. What they will get is a hugely complicated package of reforms that extends health coverage to about 30 million who are currently uninsured, and outlaws some of the worst abuses suffered by those who are underinsured, such as having their cover withdrawn when they most need it. And the stately Ms Snowe, a lifelong Republican, has her fingerprints all over it.

How did Obama’s flagship domestic initiative come to this, and where will it go from here? In a nutshell, it was ambushed by the interests that have done the same thing to every major health reform plan of the past century. It was saved by a Samaritan from the other side of the political road, and thanks to her it might just become law.

The US health insurance industry has done its best to scupper the Bill emerging from the Senate Finance Committee, as it has previous health reform efforts, including that of Hillary Clinton 15 years ago. This time the industry appeared to be on board until Senator Snowe used her clout as the only Republican thinking of backing the Bill, and slashed the fines it will impose on those who choose not to buy insurance even after it has passed.

This will cost insurers dear because the lower the penalty for being uninsured, the more the young and fit will risk going without cover. But Ms Snowe’s constituents in rock-bound Maine are overwhelmingly individuals and small businesses who dislike being compelled to buy anything, and it has been almost a mantra for the White House in recent months that what Olympia wants, she gets.

The President needed her vote not only or even mainly for the figleaf of bipartisanship that she provides. He needed it to ensure a Senate majority of 60 without which his only way of passing health reforms would have been by ramming them through Congress as an appendage to the federal budget. That might have produced a more radical Bill, but at the cost of open warfare with even moderate Republicans, and a potential drubbing at next year’s mid-term elections.

Snowe is called a RINO by the right wing of her party – a Republican In Name Only. Even so, her Senate seat is safe. She has occupied it continuously since 1994 and maintains a job approval rating above 70 per cent among Maine voters. That is thanks partly to her personal story as an orphan whose mother died of breast cancer when she was eight and father of heart failure a year later, but it is also a result of her dogged and courageous centrism.

On Tuesday GQ magazine published a list of Washington’s 50 most powerful people whose surnames were not Obama or Biden. Snowe was on it, but several places below Obama’s Chief of Staff, Rahm Emanuel, at number one. For the three hours that she kept the world waiting their rankings should have been reversed.

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