POLITICAL power is hard to win, but harder to exercise to good effect. The triumphs of an election night fade quickly. Victories in government endure for years, sometimes for generations. Those who devote their lives to wringing every vote from a contest can too easily lose sight of the fact.

It is an old conundrum. What use are grand legislative schemes if you have no power to turn them into reality? But what use is the winning of office if you use office solely to gain yet another electoral victory? One consequence is the permanent campaign, that blight of modern life.

As the Scottish National Party gathers in Aberdeen its members should take a moment to consider these issues. Justifiably, most will want to celebrate an unprecedented year. By any measure, they have a multitude of reasons to celebrate. That is all the more reason to pause.

The SNP is beyond question the dominant force in Scottish political life. Its membership growth has been phenomenal. Its General Election success defied even the party’s most optimistic predictions. It controls the Holyrood Parliament and will undoubtedly retain power in 2016. So: what next?

SNP members will have a ready answer: independence. Such, after all, is the very purpose of the party. Yet as Nicola Sturgeon knows and wiser Nationalists realise, the offer of candidates for election implies a contract. Voters expect good government now, not in an idealised future. Equally, those voters have a limited interest in past achievements. They want policies for today.

An obvious case in point: the Scotland Bill, with all its ramifications, is upon us now. It is not, let’s say, entirely to the SNP’s liking in every respect, but its implications are becoming clearer by the day. So how – to take one example – will Ms Sturgeon’s Government respond to the news that power over abortion law is to be devolved?

We know that the SNP argued for Holyrood control in the teeth of Labour’s opposition. We know that the First Minister is minded to make no changes to existing regulations. But where does the governing party stand – as a party and as a government – on the principles at stake? The SNP’s mettle is about to be tested in both respects.

It is a matter, in that over-used word, of vision. It is also a matter of a party’s purpose. The SNP’s credentials as a left-of-centre force have been decried by its opponents of late, perhaps predictably. The only possible riposte can come through deeds, not words. It amounts to a statement of political identity. What does Ms Sturgeon’s Government mean to say about itself in the tax argument, in the welfare argument, in the abortion argument?

For long enough, the SNP has depicted itself as an insurgent opposition. It continues to do so, even while running a country. Those days are passing, if they have not already passed. The challenge is this: what kind of party means to govern Scotland next year and beyond?