YESTERDAY was a very good day for anyone who has ever been employed by a political party.

You see, working for a party can be exhilarating, but there is a snag. The upside is this — you may get to be present when history is made, although in my case this mostly consisted of being in the room when people resigned or were informed of a fresh political disaster. The downside? Who is going to employ you when it’s all over? In all the years I spent at Conservative Central Office I never once saw a job advertisement that read: “Wanted: Enthusiastic person who knows just how to frame a difficult question to the Prime Minister. Essential — a clean driving licence and a freakish recall for embarrassing things once written in Tribune by Margaret Beckett.”

Karl Hess, the chief speechwriter for Barry Goldwater’s 1964 presidential campaign, went looking for work after that election was over. He was turned down by every senator and congressman he approached. He then applied to become the Senate lift attendant. When he failed to gain even this appointment, he went on a welding course and took a job on the night-shift in a machine shop. In my own darker moments I saw myself as junior public affairs assistant (the senior adviser being a Labour supporter) to North West Utilities, responsible for dragging old colleagues to partake of canapés with the finance director at party conferences.

So yesterday was a good day. A new career opportunity opened up for party professionals.

In the past few weeks the papers have been full of remarkable facts about David Cameron, yet none of them make him unique as a party leader. He is, apparently, related to the Queen, but if we go back far enough, aren’t we all? Even me (Charles II definitely looks Jewish). Mr Cameron is in his thirties, but so was William Hague when he became leader. He likes rock music, but so does Michael Howard.

What marks David Cameron out, the experience that made him as a politician and which none of his predecessors shared, is that he began his career working for the Conservative Research Department (CRD), the Tory party’s policymaking and briefing division. This makes him the first leader of any political party ever to have risen from the ranks of its professional employees.

It’s not unusual for potential leaders of the Conservative Party to have worked for the CRD. But until now, the CRD’s role in leaderships contests has been to provide the loser. Since the CRD chairman Rab Butler was first overlooked in 1956, CRD staffers Reggie Maudling, Iain Macleod, Enoch Powell, Douglas Hurd and Michael Portillo have all had their eyes on the prize but been denied. Two members of Labour’s staff have challenged for the leadership of that party — Denis Healey and Peter Shore each ran twice — but they too were defeated.

Now Mr Cameron has won. And his background as a political professional was central to his victory. The new leader’s close friends and advisers are known as the Notting Hill set, as if they all first met by bumping into each other outside the Gate cinema. In fact, the place they all met is in Conservative Central Office. Almost the entire inner circle — George Osborne, Mr Cameron’s best friend, Rachel Whetstone, his longtime ally, Steve Hilton, his strategist, Catherine Fall, his aide, Edward Llewellyn, his new chief of staff, and Ed Vaizey, his parliamentary booster — worked together for the CRD. They are the Smith Square set.

And it was their professionalism that helped their old friend to a most improbable victory. At two vital moments in the long leadership campaign — the launch event and the drafting of the conference speech — Mr Cameron’s team was simply better organised than its rivals. Only when control of David Davis’s drive for the leadership passed from MPs to two able former party staffers — Nick Wood and David Canzini — did Mr Davis stage any sort of recovery, although by then it was far too late.

It was not just organisational ability that gave the Smith Square set the edge. It was also superior understanding of Tony Blair and the way he has changed politics, gained through their work at CRD closely following his rise. The first time I met Mr Osborne was at the Labour Party conference in 1994, watching Mr Blair announce his intention to abolish Clause Four. He was the CRD observer sent to monitor Labour’s new leader. Afterwards, at lunch, Mr Osborne told me that he thought the Tory party would be forced to change deeply to meet the Blair challenge, something very few people indeed understood at that point.

So the election of Mr Cameron marks an important new stage in British politics — the triumph of the political professional. It can be seen on the Labour side too. The political success of the Blair premiership depended greatly on the quality of his staff. In the Brown era it will go further. The Miliband brothers, for example, will continue their advance. And having created all of Gordon Brown’s economic policies, Ed Balls conducts almost all of the Chancellor’s interviews now too, leaving the Mr Brown only the job of feuding with people.

Is this increased professionalism in politics a good thing? No. It makes politics too inward-looking, robbing it of the experience of others. The triumph of the party staffers has come about because the rules of politics are now so elaborate, the language so obscure, that the “game” can only be played by those who have spent a lifetime studying it. This is not a healthy development.

The Smith Square set should see one of their tasks as being to open up politics to those who do not share their expertise.

daniel.finkelstein@thetimes.co.uk

Times Recommends

• 'Tis the season for all things garish
• Don’t let auld acquaintance be forgot
• Gove’s guide to a simply glorious Christmas