For barack Obama, the past is mere prologue. From January 2011, the President will be part of an entirely new political play in Washington. Unless every poll in these last days of the mid-term election campaign is wrong, next week's vote will force him to deal with a world in which Republicans have a majority in the House and near-parity in the Senate – and in which his plans for the presidency will have to take quite a different tack. For Mr Obama's first term, at least, the time of sweeping political change is at an end.
And yet, just possibly, a Republican takeover of the House of Representatives in the midterm elections could be the making of the President. Had he powers of ESP, this President might consult the shade of Harry Truman for proof. More practically, Mr Obama could study – indeed, almost certainly has studied – how the very-much alive and thriving Bill Clinton turned that predicament to his advantage after the Republican landslide in 1994. For these last four days of the campaign, of course, Mr Obama has a record to defend, which he did during an interview with Jon Stewart on the satirical The Daily Show on Wednesday. By trumpeting healthcare reform and the other hard-won legislative victories of his first two years in office, he sought to remind the disillusioned young voters (for whom Stewart is more persuasive than any professional politician) of what he had achieved in the teeth of unrelenting Republican opposition.
Because of that opposition, whatever emerges from the incoming 112th Congress will perforce be a compromise. But that could be a good thing - not just for the President, but the country as well. Politicians may depict 2 November as a day of apocalypse (or rebirth, depending on their party). In fact, divided government is the rule rather than the exception in the US; indeed, the last president to serve an entire term with both a House and a Senate controlled by his own party was Jimmy Carter.
Perhaps not by coincidence, Mr Carter's relations with the Democratic leadership on the Hill were appalling. Ultimately he was challenged from within his own party by Ted Kennedy in the primaries, and subsequently trounced in the election. The single-term Carter presidency is generally regarded as a failure. Mr Obama does not want to follow suit – nor need he.
The conventional wisdom in Washington right now, of course, is rather different. If you detest the partisanship and polarisation of US politics these past two years, it runs, then get ready – you ain't seen nothing yet. Fanatical Tea Partiers, it is said, will gain a strong foothold in Congress and drag the Republicans further to the right, making it even less inclined to compromise. Welcome, in other words, to permanent deadlock, and endless fights over deficits, tax cuts, and social policy.
But these bleak prognostications may not come true. Yes, John Boehner, the current minority leader of the House who is all but certain to replace Nancy Pelosi as Speaker, has played hardball these last two years. But his gut political instincts are less confrontational than hers. More important still, he's been around long enough to know that with power comes responsibility.
Since 2008, Republicans have had it easy. American voters have short memories. The party has been able to watch the popularity of Mr Obama and the Democrats tumble thanks to the grim economy – even though Republican laissez-faire policies embraced by the Bush administration largely caused the 2008 financial crash and recession that followed.
Now however the public will expect Republicans not to carp from the sidelines, but to come up with answers. Mr Boehner is fully aware that victory on Tuesday is far more an unfocused scream of pain and anger against the government than it is an endorsement of Republicans.
Indeed polls show Americans still broadly believe Democrats have better policies. And here lies the opening for Mr Obama as he gears up for his 2012 re-election campaign. But first he must set the terms of the battle.
Harry Truman did that by lambasting the Republican-controlled "Do-Nothing" Congress that was elected in 1946. Two years later, he was rewarded by the most famous upset presidential victory in American history, and a Democratic sweep of both chambers on Capitol Hill.
Mr Clinton took a more nuanced but equally successful approach after the 1994 humiliation that at one point left him pleading to the country that the presidency was still "relevant", and forced him to declare that "the era of big government is over".
Instead, he shifted to the centre and worked with Republicans to pass major welfare reform – anathema to the Democratic left but proof to independents that he was not an out-of-control liberal. But he was mightily helped also by the over-reaching of Newt Gingrich, the then Speaker, whose brinkmanship over the budget led to a shutdown of government in 1995. The public, as Mr Clinton correctly guessed, blamed the Republican Congress for the impasse, and he was easily re-elected the following year to a second term.
A similar showdown could confront a Speaker Boehner if he cannot reach an understanding with the White House over taxation, spending and the deficit. Republicans will be tempted to become even more unyielding, to show that Mr Obama is ineffectual.
But this time they will share responsibility if nothing is done, at a moment when the country's problems are crying out for action. If Mr Obama can capitalise on that kind of resistance, re-election in 2012 may be a much better prospect than it might appear next week.
The man who shot the president – with his approval
As the official White House photographer, Pete Souza gets better access to Barack Obama than anyone outside of his closest political circle. Since the administration's website started posting a picture of the day one year ago, he has followed the President in every kind of situation that the leader of the Western world has to contend with – from key political moments to the endless meet 'n' greets that are a part of the job.
Yesterday Souza posted a selection of the best of those images to his blog. "The most popular pictures are ones involving fun moments with the President, or pictures of the family dog, Bo," he writes. "But we also try to show the President doing what he spends most of his time doing: running the country."