David Cameron - by common consent - enjoyed a dream start to his reign as Conservative leader.
He angered some on the right of the party by appearing to shift traditional Tory positions on immigration, grammar schools and school selection.
Elected leader: Dec 2005
Age when elected: 39
Defeated rivals: David Davis, Liam Fox, Kenneth Clarke
And he faced criticism from Labour and Liberal Democrat opponents for lacking principles and substance.
But by talking about subjects not traditionally associated with the Conservatives - such as social justice and the environment - he managed to gain the party its best publicity in years.
Even his attempts to appear young and fresh - by not wearing a tie, for example, or being photographed in a cycle helmet, did not - unlike predecessor William Hague's baseball hat - generate mocking headlines.
"The media, hungry for a new story about the Tories, have largely collaborated in portraying him as a winning guy in touch with the 21st century," wrote Andrew Rawnsley in The Observer.
"David Cameron's first 100 days can be seen as an application from the Conservative party to rejoin the human race," he concluded.
"The real truth is that it is too early to say whether he possesses the mettle of an outstanding leader".
George Jones, writing in the Daily Telegraph, said Mr Cameron's first three months had been "marked by an incredible burst of energy and luck".
"Rarely a week goes by without Mr Cameron ditching a piece of traditional Tory policy or shamelessly pinching an idea from New Labour," he added.
But, he concluded, "membership is up and so are donations. After three election defeats, even the party's traditionalists seem prepared to back a new approach if it will return them to power."
By 100 days, Mr Cameron's initial lead in the opinion polls had been pegged back by Labour, according to research by ICM in The Guardian.
But the same survey suggested voters saw the Tory leader as new and fresh compared with his "old and out of date" rivals.
Mr Cameron inisisted his changes to the party were real, not just superficial.
But the man he defeated for the leadership, David Davis, appeared to believe the Cameron revolution was more about presentation than ideas, telling The Spectator: "Under David's leadership, people now listen. For quite a long time they simply were not listening to the Tories."
He also insisted Mr Cameron's leadership was "not a swerve to the left", saying the Conservatives had always believed in, for example, social mobility and helping the less well-off.
But he said Mr Cameron's eight core principles - mocked by veteran right winger Lord Tebbit as being cribbed from New Labour - were quintessentially Conservative.
And, he suggested, the days of civil war between the left and right of the party were well and truly over.
"You will see the right of the party making arguments, not attacks," he told The Spectator.
"We are starting to see a Conservative movement."
Former Daily Telegraph and Evening Standard editor Max Hastings, writing in The Guardian, was more guarded in his assessment.
"Plenty of party activists and MPs harbour private misgivings. They were appalled when Cameron publicly renounced school selection, appeared to rule out radical reform of the NHS and downgraded tax cutting as a priority," he wrote.
"Nor do they much care for the idea that the party's Central Office will impose candidate quotas of women and gays. Eyebrows were raised about the appointment of Zac Goldsmith as a party environment guru."
But, Mr Hastings concluded: "Cameron's critics should ask: who could have done more in three months to resurrect his party?
"For everyone who wants to see the back of New Labour rule, Cameron's is the only game in town. Single-handed, he has made British politics interesting again."