The New Labour Government of Tony Blair has flown so high during its 19 months that some kind of fall seemed inevitable. But the highly popular British Prime Minister passed one obstacle after another with such confidence that he seemed immune from the normal upsets of political life.
And as Mr Blair marched on through the sunlight, his most devoted, and effective, follower - long ago dubbed the Prince of Darkness - stepped out of the shadows. Having crafted the new party and its election victory in 1997, Peter Mandelson moved this year to take charge of trade and industry and become, in his way, as important as Chancellor of the Exchequer Gordon Brown.
Mr Brown may be an awkward customer, still smarting from not having won the Labour leadership in 1994. But Tony and Peter seemed destined to walk hand in hand to fresh Labour victories and the recasting of Britain as a nation of modern social democracy with Thatcherite characteristics.
Hence the shock when an awful piece of personal misjudgement led to Mr Mandelson's resignation yesterday. It meant the breaking up of an extraordinarily successful political partnership. It also showed that the Blair administration was human, after all.
Not that signs had not been in the air. A minister resigned after being caught in a late-night encounter and robbery in a well-known homosexual cruising ground in south London. And then a former Tory MP told a television interviewer that Mr Mandelson was gay, something which had been speculated on but had not been mentioned in public.
More recently, while all the political parties banged the patriotic drum over the attacks on Iraq, there was disquiet about the way in which Mr Blair seemed to be acting as the poodle of a US president who might be trying to save his own deeply tarnished skin.