The historic nature of Monday?s 1 am US Senate healthcare vote cannot be understated. The 60-40, filibuster-breaking vote to end debate removed the last major obstacle to comprehensive healthcare reform in the US, the only industrialised nation without universal healthcare coverage. With this victory, the Senate Bill?a 2,700-page, $871 billion mammoth?is on track to be passed by Christmas Eve.

Historical precedents underscore the odds against this legislation. The subject has been debated for a century. President Harry Truman?s plan in the late forties died in Congress, Jimmy Carter?s campaign pledge was sidelined by a recession, and ?Hillarycare? under Bill Clinton didn?t survive a beating. Fifteen years passed before the issue came back for serious discussion under President Obama. Though many critics, citing the recession and two wars, have insisted that the time is not right for a major domestic reform, Obama knew that failure to act now could postpone action for decades.

The road to Monday?s vote was rough. Republicans, who staunchly oppose the reform, provided the first hurdle. Past few months have been mired in accusations of socialised medicine and scare tactics about so-called ?death panels?. While a Bill passed the House with relative ease, the Senate proved a more formidable challenge. Republicans were determined to kill the Bill at any cost, even voting against defence funding in a failed attempt to delay the Bill, hoping that pushing the healthcare vote until after Christmas break would increase the likelihood of a Democrat defecting. Ultimately, for the Bill to succeed, Senate Majority Leader Harry Reid needed to assemble the 60 votes necessary to overcome a Republican filibuster.

In the scramble for 60 ?ayes?, the President?s own party provided the second hurdle. Reid needed all 58 Democrats and both independents to secure 60 votes (although Maine Republican Olympia Snowe might have been persuadable). While most Democrats readily hopped on board, the hesitation of Ben Nelson of Nebraska, Mary Landrieu of Louisiana, and Democrat-turned-independent Joe Lieberman of Connecticut threatened to derail the Bill.

The wavering senators cited three main points of contention: the ?public option? (a government-run healthcare programme), extension of Medicare (health insurance coverage for the elderly) to people as young as 55 and public funding of abortion. Ultimately, the public option and Medicare extension were removed, and an abortion compromise was reached. To sweeten the deal, special provisions were added in favour of states with ?swing? senators, such as a $300 million increase in Medicaid (health insurance for the poor) funding for Louisiana.

But the process is not over and success is not guaranteed. After a series of votes this week, a final Senate vote will be held at 7 pm on Christmas Eve. Once the Senate Bill has passed, the House and Senate must agree upon a Bill that can pass in both houses, reconciling differences like the public option, which was included in the House Bill. If the compromise Bill passes both houses, Obama will sign the new legislation early next year, but the Bill wouldn?t take effect until 2013 or 2014.

After a year of plenty of bad news (a defiant Iran and escalating involvement in Afghanistan) and only partial victories (an order to close Guant?namo Bay that won?t meet its deadline, a recovery without jobs and a Nobel Peace Prize universally judged as premature), Obama needs a win on healthcare. Not only would it allow him to paint a slightly less dismal picture of his first year in office, but it would also prove that he is capable of defying the odds. In succeeding where so many have failed before, he would show that for once, a candidate?s promises of change and reform, of breaking through the stalemate in Washington, are not empty.