Steve Richards: Now that he is leader, Clegg cannot afford to trip up in the ways he did as a candidate

Each party has changed its leader since the general election. The Liberal Democrats have done so twice. Within the space of two years, they have leapt from Charles Kennedy to Sir Menzies Campbell and now on to Nick Clegg. Kennedy and Campbell won by big majorities. Yesterday, Clegg won by a whisker. Even at their third attempt, it seems that the Liberal Democrats are not entirely sure who they want to lead them.

The party's impatient quest and yesterday's knife-edge result are more than a reflection on the inadequacies of Clegg's two predecessors and on his own erratic leadership campaign. When leaders change frequently, there are more fundamental causes. In the case of the Lib Dems, it is the more challenging political context in which they struggle to make an impression. The closeness of this latest contest also suggests that the party is not entirely sure what sort of impression it wants to make. A confused party tends to move from one leader to another whether the context is challenging or not.

Oddly, this contest has seen the acting leader, Vince Cable, and the defeated candidate, Chris Huhne, enhance their reputations, while the actual winner has emerged with fewer glowing reviews than either. Of course, Cable flourished as acting leader partly because he had nothing to prove. Huhne also entered the contest as the expected loser and therefore could only go up.

Still, Clegg should take notes from the performances of both Cable and Huhne. The former acting leader and the defeated candidate are trained economists equipped with the confidence that seems to come with expertise in this particular policy area (look at the economist Irwin Stelzer, a quote from whom bizarrely led the BBC's 8.30am headlines yesterday). At their most effective, Cable and Huhne are distinctive and authoritative, two qualities that must go together for a party to make its mark. Both are also street fighters, unexpectedly so in the case of the once saintly Cable.

In particular, Cable has made the running on Northern Rock because he is well qualified to make a judgement and spoke with conviction. After the stellar performances of Cable and the closeness of yesterday's result, Clegg must move fast to establish his authority as a national leader.

Yet what does it take for a Lib Dem leader to successfully assert authority? For the other two parties, the answer is always the same. A leader is expected to win an election, preferably the next election. Not even the most starry-eyed Liberal Democrat expects Clegg to do that.

In terms of policy, the party makes a distinctive pitch which Clegg is well placed to articulate. For all their irascibility, both Clegg and Huhne were in agreement about the most effective ways of delivering local services, the appropriate levels of public spending and the need for more investment to be focused on the poorer areas. They are pro-European and genuinely green, in contrast to some in the bigger two parties who started to take notice of the environment only for expedient reasons after the last election.

Towards the end of the hustings, Clegg made the meatiest speech of the campaign in which he navigated what Tony Blair would have called a third way between the Tories' attachment to a smaller state and Labour's commitment to centralised control. He described his third way as individual empowerment combined with social justice. In government, he would find such a balance extremely difficult to achieve. Labour has agonised over how to bring the two concepts together for a decade. Blair and Brown rowed about this theme more than any other: how to achieve local innovation while ensuring fairness and value for money that is raised centrally through the tax payer? The answers are not easy.

Still, advocating such a balance is a sensible position for Clegg to take, calling for local accountability, decent levels of investment and encouraging the use of more providers away from the centre. More specifically, Clegg argued for the level of spending on schools in poorer areas to match the amount per pupil in private education, a policy that Brown should implement even if Clegg has not explained how he would pay for it.

Clegg has distinctive policies and, with Cable and Huhne rising in reputation, he has a senior team to compete with the other parties. But his party will remain in third place at a national level, one of the few certainties in British politics. The Liberal Democrats are not going to take over from Labour or the Conservatives, which is why Clegg will be pressed to say which of the two he can work with.

This weekend David Cameron made some overtures, probably in the hope of stifling the Liberal Democrats, rather than working with them. One of Cameron's main objectives from the start of his leadership has been to destroy the threat posed by the Lib Dems. He speaks their language and adopts some of their themes, even if his actual policies remain rooted on the right.

Meanwhile, some of those around Gordon Brown see little difference between most Lib Dem MPs and Labour. They wonder still whether the two parties could form an ill-defined progressive consensus. They wonder also whether a merger is a more desirable option, Tony Blair's hope when he danced with Paddy Ashdown for several years. They too would like to smother the Lib Dems given a chance.

None of this is going to get close to happening unless there is a hung parliament after the election. In the current climate, Clegg is hardly going to embrace a governing party that is sinking in the polls. At the same time, his party would never let him do a deal with the Tories. As matters stand, his members would have a say as to which party the Lib Dems should join in a coalition, along with his Shadow Cabinet and the parliamentary party, the so-called triple lock that makes any coalition-making almost impossible.

So Clegg must take the familiar route of going it alone, seeking the maximum seats in a climate where much of the focus will be on the battle between Brown and Cameron. Clegg has the youthful charm, the energy, and later in the campaign made some substantial speeches. But earlier he showed too easily that Sir Ming's sudden departure had taken him by surprise and he was not fully prepared. In interviews, some of his answers were too vague and not properly thought through. In his victory speech, he spoke of ambition and change, terms always deployed at the start of a leader's term (remember Gordon Brown citing "change" repeatedly on day one of his leadership, as did Cameron and Blair).

Clegg is clear about the nature of the change he seeks, but how will he bring it about? As a leader, Clegg cannot afford to trip up as he did occasionally as a candidate. The stakes are high. After all, the Liberal Democrats cannot search for a fourth leader before the next general election is called.

s.richards@independent.co.uk