Politics 16 February 2012 Cameron's state of the union flop The SNP will be delighted with the Prime Minister's lacklustre speech in Edinburgh. Sign up for our weekly email * Print HTML Even before David Cameron delivered his speech in defence of the union in Edinburgh this afternoon, the Scottish National Party had already dismissed it as "threadbare and outdated". In retrospect, the nationalists could have added "ill-informed" and "underwhelming" and they still would have fallen slightly short of the mark. It's safe to say that the Prime Minister's attempt today to develop a positive case for Scotland to remain within the United Kingdom probably won't be remembered as one of the turning points in the debate about Scotland's constitutional future. On the contrary, Cameron gave the distinct impression of someone who hadn't seriously examined his opponent's arguments. At times, in fact, he gave the impression of someone who hadn't really examined his own. "Scotland", he said, "is richer and fairer as part of the UK". But the facts simply don't back this up. Over the last 35 - 40 years, North Sea oil production has generated as much as £300bn in tax revenues for the UK Exchequer, yet Scottish rates of income inequality have skyrocketed while social mobility has stagnated. Only a Home Counties Conservative could describe that as "fair". The emotive elements of Cameron's address were similarly unpersuasive. "The link between our nations is a precious thing. It's about our history, our values, our shared identity". Well, of course. But just because two nations share some sense of an identity it doesn't mean they should also share a government, a parliament or a constitution. Few would deny the strength of the cultural relationship between Britain and Ireland. Fewer still believe the latter should re-join the UK because of it. Indeed, from a nationalist perspective, Cameron's decision to emphasise the common historical experiences of the Scots and the English will be seen as an indication of the intellectual weakness of unionism. Alex Salmond knows that the referendum will be won or lost on political and economic, rather than sentimental, grounds. Unionists should be worried that their leaders have not yet come to the same realisation. Worse still, in claiming that the provisions contained within the Scotland Bill would give the Scottish Parliament tax raising powers "for the first time", Cameron revealed his poor grasp of the details of the current devolutionary settlement. Holyrood already has the power to vary income tax rates by 3p in the pound. In reality, nationalists are quietly delighted with Cameron's apparent eagerness to be involved in the referendum campaign. The Tory brand remains contaminated north of the border and, since Thatcher, attempts by the Conservative Party to influence Scottish opinion have come across as hectoring and belligerent. What's more, every trip Cameron makes to Scotland serves as a reminder of how thin his mandate in the country is. It is common knowledge that support for the Tories in Scotland has fallen steadily over the last six decades. It less well known that if the coalition survives for the duration of this parliamentary session, Scots will have spent almost as many post-war years ruled by Westminster governments they didn't vote for as those they did. This "democratic deficit" was one of a number of important issues Cameron failed to mention in Edinburgh today. But why would he? Before it became apparent that the union was genuinely under threat, the Tory leader had shown little interest in -- and therefore developed little understanding of -- Scotland and Scottish affairs. That absence of understanding -- on full display earlier -- will do the unionists no favours as the 2014 vote draws closer. Don't be surprised if Salmond is already busy trying to arrange the next the prime ministerial visit. › Academies: five things they don't tell you, from Mehdi Hasan Subscribe More Related articles For the Ukip press officer I slept with, the European Union was Daddy As Donald Trump once asked, how do you impeach a President? Commons Confidential: What happened at Tom Watson's birthday party?