By the end of the long and tortuous route to election day , thousands of polls will have been taken, millions of miles travelled and hundreds of millions of dollars spent. Finally, on 5 November, nine months almost to the day, America will learn the identity of the president who will lead it from the American Century into the 21st century.
Rarely has a presidential election been harder to read. With the Soviet Union vanished, America is at peace, its diplomatic and military pre-eminence unchallenged, its concerns exclusively domestic. One year ago, Mr Clinton appeared doomed, his Democrats utterly vanquished by Newt Gingrich's Republicans in the mid-term Congressional elections of November 1994. The results seemed to prove that the country had moved decisively rightward; but has it? Can the Republicans complete their conservative revolution by regaining the White House?
In the past 12 months the Republicans, vigorously pursuing their mission to slay Big Government, have seriously overreached themselves.
Mr Clinton, after almost disappearing from view for several months, has re-emerged to play brilliantly on public fears about the future of federal health programmes, education and the environment. Every sign is that the public believes Mr Gingrich and his men want to go too far, too fast. Contrary to the cherished tenets of their history, Americans are no longer political revolutionaries. Here, as nowhere else, checks and balances are built into the system, and elections won and lost in the centre. This year could prove anew that, for all their complaints about "gridlock" and a government that does not work, Americans secretly prefer that supreme check and balance - a government divided between the major parties.
If he prevails, Mr Clinton will become the first Democrat since Franklin Roosevelt, more than 50 years ago, to be elected for a second term. At this early stage, the President must be favoured, albeit narrowly. Despite the vicissitudes of his three years in power, Mr Clinton is a lucky, as well as an intensely skilful, politician. He is a marvellous campaigner too, a gifted speaker who can trounce in debate any Republican in the lacklustre pack on offer.
Fortunate indeed is a sitting president who faces neither a primary challenger from within his own party nor a charismatic champion from the opposition. Jimmy Carter, the last Democrat to seek re-election, was, on the whole, better loved than Mr Clinton but he lost. He was weakened by an internal challenge from Edward Kennedy in the primaries in the spring and was finished off by the rise of Ronald Reagan in the autumn.
With Mr Clinton, nothing can be counted certain. Nearly half the electorate say they do not trust him. The foibles of his private life are well-documented and his political persona is slippery as ever: the man who ran in 1992 as a "New Democrat" then governed as an old-style liberal Democrat, stole Republican themes by the dozen in his recent State of the Union address. And in the wings, obscure but unpredictable, lurk the confusing but stubborn allegations of financial misconduct in his Arkansas days, known collectively as Whitewater.
But first the focus is on the Republicans as they select their nominee. For all the thunder they have generated on Capitol Hill, the party's storm- troopers have no true representative in the field. Speaker Newt Gingrich, their now-tarnished champion, is not running (too unpopular). Other media favourites, such as General Colin Powell, could not face the sheer nastiness and complexity of the process. Bob Dole, the early favourite for the nomination, is a reluctant revolutionary at best, while Mr Dole's main early challenger, the millionaire publisher Steve Forbes, is not a politician at all. The rest are nowhere.
Two of the over-arching themes of Campaign '96 are clear. One is the basic philosophical argument over the size and role of government. The debate embraces the burning issues of the moment: the clamour for a balanced budget and lower taxes, the unending criticism of Washington and its ways, and the myriad proposals to shift power from the centre to the states.
But an enduring paradox muddies the argument. Much as Americans detest government, they have grown to love the benefits and safety-nets which government offers.
And so to the other leitmotif of this election year, on which few candidates care to dwell. It is fear - more exactly economic fear, deriving from corporate down-sizing, the disappearance of jobs that had been safe for generations, and the dawning realisation that Americans are no longer guaranteed an eternally rising standard of living in which each generation aspires to a more comfortable existence than the last. Wall Street may be booming, but Main Street USA is frightened. The well-heeled novice Steve Forbes prospers because, for a while at least, he can conjure away these concerns with his talk of a flat tax to cure the nation's ills.
Of the other candidates, only Pat Buchanan explicitly addresses the issue, with his call for controls on immigration, and an economic Fortress America.
Nor may November's run-off be limited to the contenders of the leading parties. With the Republicans and Democrats having feuded and failed to balance the budget, the opening is there for another millionaire, Ross Perot, who convulsed and then disappointed the nation in 1992, to make another independent run, this time at the head of his own party.
And what happens if Mr Dole folds and the Republicans weary of Mr Forbes? Could they turn to one of the notables who (probably wisely) decided not to subject themselves and their families to the savage ordeal of a Presidential campaign - Jack Kemp, Dick Cheney, or even General Powell, the man with the best chance of beating Mr Clinton? The prospect of a late entrant being brokered into the nomination at the Republican convention is remote, but not impossible. Election 1996 could yet prove to be a rollercoaster.