At a special conference to decide how a new party leader would be elected in June 1976, the acting (and previous) Liberal leader Jo Grimond declared, tongue-in-cheek, that "it would really save a lot of trouble" if he just stayed on. He could not countenance doing so, however, he said. For that would deprive his audience of "this top-hole day in Manchester . . . There is nothing that Liberals love more than a long day of constitutional wrangling."

Grimond was right that Liberals are much given to the pastime, and frequently in a manner that belies their image as nice but ineffectual. (I vividly remember the bulging faces of those who tried to shout down the former SDP stalwart Celia Goodhart as a "Tory" at the first Lib Dem conference I attended in 1989.) But wrangling, whether of the constitutional or of the ideological variety, is just what the Liberal Democrats need to avoid during this conference; and, in particular, wrangling about the rights and wrongs of allying with the Tories.

For there has, right from the start of the Lib-Con coalition, been much talk of "betrayal". This is nonsense. A betrayal of Liberal principles would have been to trim and discard them in an attempt to woo the voters before the election. (This, of course, is the history of the whole New Labour project, which fully deserved that abusive word, and many others, too.)

But this is not what happened. Liberals fought and won on a Liberal manifesto, meaning that in a hung parliament they could then negotiate from a position where it was clearly understood that that manifesto was endorsed by a certain percentage of the electorate.

The cards in their hand were openly won. Equally openly, some had to be given away in order to form a government with a different party possessing a different suit of cards.

There may be debate about the number of cards conceded. The idea that no trade at all should have been done, however, and that Liberals should remain in splendid, untarnished isolation, would be to reduce the party to a receptacle for protest votes or, at best, suggest that its ambition was no more than to be some glorified think tank, whose ideas the other parties could then pinch and take the credit for.

Liberals should remember the words of David Steel who, making his own, successful bid for the party leadership in 1976, said:

We should combine our long-term programme with a readiness to work with others wherever we see what Jo Grimond has called the break in the clouds -- the chance to implement Liberal policies . . . There are occasionally small "l" liberals to be found outside the Liberal Party, and we should never fear to co-operate with them effectively to promote some part of our cause.

Later that year, in his first address to the Liberal Assembly as leader, Steel pursued the theme:

I want the Liberal Party to be the fulcrum and centre of the next election argument -- not something peripheral to it. If that is to happen, we must not give the impression of being afraid to soil our hands with the responsibilities of sharing power.

We must be bold enough to deploy our coalition case positively. We must go all out to attack other parties for wanting power exclusively to themselves, no matter on how small a percentage of public support.

The following year, Steel had led his party into the Lib-Lab pact with the Callaghan government. The NS's then political columnist, James Fenton, put the reaction of the Liberal Assembly to this small taste of reality charmingly:

Old habits of thought die hard, and the old habit of Liberal thought is abstract hope, a hope that, like Hamlet's chameleon, eats the air, promise crammed. Liberal thought is not used to discussion of tactics or deals. It finds it difficult to concentrate, period. That is why Steel, in addressing the party, has the air of a teacher, but a teacher whose points are continually being missed.

What was that he said, for instance, about a coalition? "Now we have to demonstrate that if this much can be done by a tiny band of Liberals outside the government, how much more could be done by a larger group inside the next government." Did he really say that? What does it mean?

Liberals know -- how could they not, given their history? -- that they will never get to glory in the sun on their own. Nick Clegg found his break in the clouds. Over the next few days his party's task is to help him exploit that for all that they can.

It would be foolish and self-destructive, and ultimately, proof that a vote for the Liberals is a wasted vote, if delegates spent all their time bemoaning that the weather did not turn out differently.