Here’s a way to get the British not to vote for your party: elect a rich Eton-Oxford toff as your leader. In the pub and on comedy shows the toff remains a primary target of abuse. The masses cry: “We hate toffs, we want leaders like us!”

But we don’t. We want David Cameron. He’s a toff. But here he is, the Conservative leadership frontrunner, the Tory Blair. What happened?

Well, here’s a theory. On BBC2’s Newsnight at the start of the Tory conference an American named Frank Luntz conducted a focus group on the leadership candidates. Liam Fox seemed to be in front because the poor saps thought he was “like us”.

But when Luntz showed a film of Cameron, everything changed. The group loved him. Real-time charts showed their adoration soaring with every word. This is, cried Luntz, apparently close to sobbing, “the best segment I have ever tested in politics!” Cameron was launched.

There are two things wrong with this picture. First, focus groups are rubbish. I once sat in on one. I could have talked the poor fools into believing there was an elephant in the room. Second, Luntz seems to be parti pris. He went to Oxford where, at the time, Michael Gove, now a key pro-Cameron MP, was Union president, the successor to Boris Johnson, also now a Cameron man. Nick Robinson, the BBC political editor, who was among the voices talking up Cameron at the conference, was there at the same time.

Suddenly — at least in the eyes of the unofficial David Davis-supporting website daviddavisleader.blogspot.com — the whole Cameron thing is the most monstrous media stitch-up. It’s just another old-boy network designed to keep non-toff Davis out, right?

Wrong. Something much more interesting is going on here.

Everybody has at least one network, almost everybody has many. Alexander McQueen and Robbie Williams didn’t defend Kate Moss in her season of cocaine hell because of intellectually considered positions. They did so because they were her pals.

Moss’s network consists of everybody who has fleetingly felt blessed by her presence as well as millions of young people who want to feel they know her. The brilliance of Williams’s intervention — he pointed out that the hacks attacking her had in the past taken cocaine with her — was that it appealed over the heads of the media to her big open network to rally round.

The key term here is “open network” because it is now clear — to Cameron, to Blair, to everybody in the socio-political know — that the exclusive “closed networks” of old are useless.

Luntz started his report in the Carlton club. He called it “the Conservative home”, but he knows it isn’t. The old London clubs are mausoleums with bad food. Nothing happens there and nothing will. They are “closed networks” that have died.

Almost 40 years ago, Mark Granovetter, now professor of sociology at Stanford University in California, started asking his friends how they found jobs. He assumed they got them through close friends. But no. Consistently, jobs were found via acquaintances, people they knew but not necessarily well.

In 1973, Granovetter outlined his influential theory in a paper called The Strength of Weak Ties. He had found that closed networks fail because they cannot acquire new blood and new ideas from outside. Looking for a job in a closed network is difficult because your fellow members will only have the same information as you have.