IT'S hard to think of anyone that the First Minister less resembles, than the actor-turned-Republican President, Ronald Reagan – apart perhaps from Margaret Thatcher. It is a poor reflection on the political wisdom of Scottish Labour leader, Richard Leonard, that he's compared Sturgeon to both those icons of the political right in the past two weeks.

It was at an unusually stormy First Minister's Questions on Thursday that Mr Leonard accused Nicola Sturgeon of being a follower of “Reaganomics” because she allegedly wanted to cut public spending in order to push through a tax cut for the rich. Actually, Reagan presided over a big increase in public debt in the 1980s. And Sturgeon didn’t axe the 50p tax band: the Conservatives did.

What the Labour leader really meant was that Nicola Sturgeon had become a follower of the now largely discredited “Laffer Curve” theory that increasing taxes beyond a certain point reduces revenue. This is because wealthy people can avoid paying high taxes, either by leaving the country or by hiring accountants to get round paying it.

There is no such economic law. However, in particular circumstances, in cities, regions and small countries, tax flight can be a real problem. Look at what happened to the centre of Glasgow in the 1960s and 1970s when middle class ratepayers left for the suburbs and slaughtered the tax base. The First Minister is right to be cautious about increasing taxes in Scotland because there is a very porous border just 50-odd miles south of Holyrood.

Only around 20,000 people would be liable for the 50 per cent “additional rate” tax band on £150,000-plus incomes, were it to be reintroduced in Scotland alone, as Leonard urged the First Minister to do. And while I don’t think many of them would actually leave, it would be irresponsible of Nicola Sturgeon to reject the advice of her statutory Fiscal Commission that the vast majority of Labour’s claimed extra £1bn in tax revenue would be lost through “behavioural changes”. We don't want even more of Scotland's wealth to disappear into the south of England.

This does not mean that increasing taxes on people on higher incomes is a bad thing. On the contrary, it is very much in the spirit of the times, and the First Minister is doing it. She has broken the decades-long taboo on raising taxes on people paying the higher rate and even on some paying the standard rate. Under the Scottish Government's policy, largely inspired by Green Party MSPs, the tax bands have been altered so that no-one earning below around £30,000 a year will pay more, and those above that limit will pay progressively more.

Leonard may see this as tantamount to the policies of Ronald Reagan and Margaret Thatcher, but Conservative-leaning newspapers certainly didn't see much resemblance, and nor did the Scottish Tory leader, Ruth Davidson. The headlines have all been about the Scottish middle class being “hammered" by the SNP’s “tax grab”. This is precisely the reverse of Reaganomics and indeed Thatcherism, which was all about cutting taxes. In the 1980s, the Tories cut taxes by historic amounts, slashing higher-rate income tax from 83 per cent to 40 per cent and introducing all manner of tax cuts for the better off. The great inequalities of wealth we see today are a direct result of those tax cuts.

But here's the thing: Labour continued and extended those low tax policies right through the party's longest period in office, between 1997 and 2010. Gordon Brown introduced some stealth taxes, but he never touched income tax, except to reduce it marginally. Indeed, we learned from Brown's biography that Tony Blair wanted to cut the top rate of income tax even further, to 35 per cent. It was the former Labour Industry Secretary, Peter Mandelson, who famously said that Labour was “intensely relaxed about people getting filthy rich so long as they pay their taxes”. Unfortunately, they didn't do a great deal of that, thanks to Gordon Brown's famous “light touch” regime in the City of London.

As recently as 2007, on the very eve of the financial crash, Brown – the longest serving Labour Chancellor in history – praised City of London bankers as “champions of diversity in ownership and talent” who had created a “new world order ... perhaps even greater than the industrial revolution”. Well, we saw what happened to that. Four months later, Northern Rock collapsed, and Britain entered the Great Recession, from which we have never fully recovered. Workers have suffered the longest period of wages stagnation since the Napoleonic wars, while the state sector has been ravaged by austerity.

But what’s worse, when Gordon Brown became prime minister in 2007 he left the privileges of the bankers intact, including their bonuses and £multi-million salaries. He simply pumped taxpayers' money into the corrupt City of London, and let them carry on exactly as before. And let's not start on Labour's enthusiasm for the Private Finance Initiative, the legacy of which has been seen in Carillion.

Richard Leonard's supporters insist that this is all ancient history. We can change, they say. Now Labour want to crush the rich till the pips squeak. But it is natural that voters are sceptical, especially since supporters of Tony Blair remained in charge of the Scottish party until late last year. And anyway, simply striking postures about higher tax, and making threatening noises about imposing arbitrary wealth taxes on pensioners earning relatively modest incomes, is not the way to win support from the voters. Rather it creates a sense that Labour is a party with a divided mind and a detachment from reality – which in many ways it currently is.

On Brexit, too Leonard is all over the place. He was one of only three MSPs who voted with the Conservatives in favour of triggering Brexit in the Holyrood vote in February 2017. He now appears to be supporting continued membership of the EU Customs Union. He is a very decent man, with very limited political experience, doing an extremely difficult job, but that doesn't mean you can get by without doing the homework – certainly not against the most astute Scottish political leader in modern history, Nicola Sturgeon. The SNP bolstered their commanding lead in the polls last week, while the Scottish Conservatives continued to slide.

There are definitely signs that we have passed what pundits call “Peak Ruth”. Davidson may have gained 12 MPs, as she boasted last week, in the June snap election, as she capitalised on the First Minister's misjudgement over indyref2. But there is no evidence that the Tory recovery is enduring. Davidson had hoped that the First Minister's tax increases would guarantee more Tory votes, but that looks forlorn. The opinion polls suggest that voters see the Scottish Government's tax policies as both responsible and fair. That is a great achievement.

The debate about tax now moves to local government, and reforming the council tax, which has for years left those in large properties under-taxed for too long. So let's have that discussion. But the left in Scotland really needs to stop assuming that, just because the SNP are in government, everything they do is wrong. It's good to hold governments to account, of course. But when they get something right, as on tax, the sensible thing is not to indulge in knee-jerk opposition, or make facile comparisons, but to claim moral credit for it.