The scale of Hillary Clinton's victory in the New Hampshire primary is hard to underestimate. On the morning of the election, opinion polls were showing her trailing her Democratic Party main rival Barack Obama by between seven and 13 percentage points. Yet when polls closed, she was the victor. In an extraordinary turnaround, Ms Clinton garnered three percentage points more than Mr Obama.
Not since the infamous Chicago newspaper banner headline in the 1948 presidential election - Dewey Defeats Truman - have the pollsters and pundits got it so wrong. Ms Clinton has already dubbed herself the campaign's "comeback kid", echoing her husband's claim when he finished second in the 1992 New Hampshire primary but went on to capture the White House. And while more attention has been given to the Clinton/Obama fight, the Republican Party delivered its own surprise in New Hampshire. For them, the comeback kid was the sprightly 71-year-old Senator John McCain. He finished a poor fourth in Iowa but in New Hampshire, took 37 per cent of the Republican votes to Massachusetts Governor Mitt Romney's 32 per cent, with Arkansas Governor MikeHuckabee commanding just 11 per cent support.
Why - and how - Ms Clinton reversed her fortunes will keep analysts and opinion pollsters occupied for some time. Her uncharacteristic show of emotional fragility laced with patriotic commitment on Monday may have struck a chord with some voters. What is clear, however, is that older voters, female voters and core Democrat supporters rallied to her at the moment of actual voting and delivered a victory that even Ms Clinton's campaign thought was not to be theirs.
On the Republican side, cash-strapped Mr McCain seems to have stolen a march on his rivals by concentrating only on New Hampshire and staging over 100 low-key, inexpensive town hall face-to-face encounters with voters that endeared him to party supporters. But the hunch remains that whoever the Republicans choose, this presidential race is for the Democrats to lose.
In the coming days - on January 15th, 19th and 26th - there will be further elections in, respectively, Michigan, Nevada and South Carolina. (There is also a primary due in Florida on January 29th but, because of a row, the Democratic Party national committee may seek to exclude Florida delegates from the convention that will endorse the party's candidate for the White House.)
For now, however, all eyes will be on Super Tuesday, February 5th, when over 20 states, including major delegate delivering states such as California and New York, will hold primaries or caucuses. If core Democrats everywhere rally to Ms Clinton, she may find that New Hampshire was the sternest test in her quest for nomination. To beat her, Mr Obama will need to inspire young voters, uncommitted voters and swing voters as never before. A fascinating contest has got under way for the most powerful job in the world.