Seven months ago Washington heaved with Obamamania. Millions crammed onto the Mall in arctic temperatures to bask in the warm glow of history.
What followed was a fascination with every detail of the First Family’s life, from Michelle’s vegetable garden on the South Lawn of the White House, to the attributes of a Portuguese water dog called Bo.
The president spoke eloquently about the need for radical reform on the economy, the environment and foreign policy.
He redefined America’s relationship with the world.
With a flick of a pen he declared the intention to close down Guantanamo Bay. He reached out to staunch enemies like Iran without sounding craven. He began to talk to the Muslim world rather than at it.
And in case anyone thought he was going soft, he also had some Somali pirates shot who had dared to take an American sea captain hostage.
He remained more popular than his policies, but by and large the country which had ushered him into the White House was still prepared to give him the benefit of the doubt.
My neighbour Dave, a Republican lawyer who had voted twice for Bush, but defected to the Democrats last year because he could not stomach the thought of Sarah Palin being one heartbeat away from the Oval Office, was not nearly as weak-kneed as the average Obama groupie. But he was an Obama Republican.
Dave was a newly minted member of the biggest tribe in American politics: independents. According to Gallup polling, they now outnumber people who describe themselves as staunch Republicans or Democrats.
Mr Obama had sealed Dave’s vote. But he had not earned his enduring loyalty.
Today, Dave is one of millions of independents who are increasingly disenchanted with the 44th president.
He fears that Mr Obama has taken on too much, too fast, too expensively.
An innate conservative, Dave is irked. He is a cautious man, rattled.
As the centre-right columnist David Brooks put it the other day in the New York Times: “No newly elected American president has fallen this far this fast.”
This may be an exaggeration, but something has clearly malfunctioned in this administration beyond the usual honeymoon hangover.
I think it started to go wrong at the time when Mr Obama was joking about the disproportionate fuss made over his first 100 days in office. He quipped about completing his second 100 days in 72 days, and resting on the 73rd day.
But Mr Obama’s summer has been far from restful.
So what has happened? The summer hole has not helped.
For politicians, August can be the cruellest month. Nothing is decided. Almost everyone is on holiday or thinking about it.
The president cannot do much. He can only talk. It is almost impossible to escape the impression of torpor and inertia.
That is why Obama was so keen to get healthcare signed, sealed and delivered before the summer. Having failed to do so, his opponents have had a field day in redefining the debate on their terms.
Healthcare reform - or rather opposition to it - has become a lighting rod for a whole host of grievances, fuelled by the economic crisis, leavened by political defeat, rubbed raw by a sense of victimisation.
This summer has seen the rebirth of the angry white man and woman. Their fear and anger, some of it legitimate, much of it exaggerated, have not been channelled by any political leader - the Republicans continue to leave that position unfilled.
It has been nurtured on talk radio and cable television like an exotic plant.
The sobbing and sardonic Glenn Beck on Fox News has become the shrillest voice of Main Street discontent. The ratings prove the point.
But for the administration, the problem is potentially far more serious. After all, Glenn Beck and his crowd never liked this president anyway.
It is the wobbly Obama Republicans - like my friend Dave - that he really needs to worry about.
Ironically, the gradual improvement in the economy is not helping.
The panic is over and the market is up - that is good. But the dark days of February and March, when America was curled up in the foetal position, baying for help, were a great opportunity to push through a radical agenda.
If you are hurling billions at the bail-out, why not rearrange policy on the environment and healthcare? If you are giving Uncle Sam CPR on the operating table, why not use this golden opportunity to give him a stomach pump, a skin graft and, yes, a nose job?
Now that the pulse has come back, the patient has woken up, become more cautious and said: hang on a minute!
Congress has not helped by acting - as it always does - much slower than the White House and public opinion.
If there is a passionate mood on the streets of America for change to be conceived, you can be sure that the in-fighting and hand-wringing in Congress will act like a political contraceptive.
The Republicans become masters of trench warfare. The Democrats become experts at retreat. And as the 2010 campaign looms, both are egged on by fears of not getting re-elected.
Finally there is the perpetual Gordian Knot of American politics: healthcare reform.
So many presidents have tried to untie it. So many have failed.
Perhaps Mr Obama will still succeed. But what counts against him is that the majority of Americans still believe that the risks of overhauling the system are greater than its faults.
The fact that 46 million Americans are uninsured and half as many under-insured is an outrage, but one that affects the lives of others.
So next Wednesday, President Obama will mount the stage once again and grab the limelight by going before a joint session of Congress in a prime-time address.
The audience will be more wary and tired than it was last time he gave such a speech in February.
Mr Obama will have to find soaring words and then - once the polite applause has petered out - use all the arm-twisting, emotional bribery and political deal-making he can muster to deliver a result that he can call a success.
If not, the vultures will continue to circle. Oh yes, and no more town-hall meetings please.