THERE, you see: it twitched.

It definitely did. The prone and lifeless body of the Scottish Conservative Party has been showing indications of life, though perhaps not as we know it. But there are signs of motor skills returning with the new Scottish Tory leader, Ruth Davidson.

Yes, I know, she's not exactly been a raving success at Question Time in the Scottish Parliament, where Alex Salmond has started being polite to her – always a bad sign. But few voters tune in regularly to FMQs and appearance on TV counts more. Ms Davidson looks and sounds so unlike any Scottish Conservative of the past, you can't help thinking that the Tories must have changed from the introverted, homophobic, golf-and-RAC club party. Unfortunately, it's not clear what they have changed into.

If only they had a sensible political message to sell they might even be back in business. But they don't. Tomorrow, Ruth Davidson will launch her "Friends of the Union" campaign, as the Tories traipse to Troon to show that they are just like the rest of us and not just posh Perth farmers and Edinburgh bankers. (I wonder if the local Labour MP, Brian Donohoe, will take up the challenge of appearing on the same Unionist platform with David Cameron as he rashly suggested at PMQs last month?) But the conference has already been upstaged by the Budget and George Osborne, confirming the blindingly obvious proposition that if the Scottish Tories want to stop being political pariahs in Scotland, they have to make a break from the party of the same name in England. Every March they'll get tarred with the same Eton-educated, 50p-tax-cutting, mansion-living image of the UK Chancellor.

They were offered a clean break by the defeated Scottish leadership candidate, Murdo Fraser, who wanted to scrap the party and start again under a new name. They rejected that in favour of fresh-faced Ruth Davidson. They had another chance when David Cameron came north in February to crush the Nats, and somehow ended up conceding more powers for the Scottish Parliament. That's the moment they should have embraced devolution-plus. The Scottish Tories had another chance in the run-up to the Budget, when they could have made clear that they did not think cutting tax for people earning over £150,000 was a political priority in Scotland right now.

But the trouble with the Scottish Tories is that they're too compliant, too ingratiating, too eager to please their masters. They're like those Scottish Tory journalists who used to write articles calling for the Scottish Parliament to be scrapped. They think that old-school Unionism is what London wants to hear. Yet if they only listened to what Westminster Conservatives are actually saying they'd realise it isn't. Die-in-the-last-ditch Unionism is of no use to David Cameron, who finds Scotland a painful embarrassment – that gag about there being more giant pandas than Tory MPs. George Osborne is reported to be quite keen on the idea of devolution-plus – essentially giving the Scottish Parliament full tax powers, but retaining VAT and National Insurance at Westminster.

The Scottish Tories have failed to capture the devolution-plus agenda and claim it for themselves. Which is bizarre because it is the brainchild of the Conservative-leaning Reform Scotland think tank and its awfully well-spoken director, Ben Thomson, who reminds me a little of the late Alick Buchanan-Smith, the best Scottish Secretary the Tories never had, who fell out with Margaret Thatcher over devolution. Ruth Davidson has retreated to the old nonsense formula of "real devolution" – putting more power in the hands of "real people". All we need is for her to start insisting that devolution isn't an issue on the doorsteps and we'd be right back to the 1980s and Malcolm Rifkind.

No, this won't do. The Scottish Tories can't afford to be Friends of the Union, when no-one knows what the Union is any more. The status quo is dead. Following Facebook, they should unfriend the Union. Forget the nonsense about "drawing a line in the sand" at the Scotland Bill. Ms Davidson should state the obvious: that the Calman-inspired Bill is not fit for purpose. The Scottish Tory leader should be arguing not only that the Scottish Parliament should have the power to cut corporation tax, but the power to cut income tax in Scotland to promote growth. (Though not just for people earning six times the median full-time salary in Scotland.) Whisper it, but the Scots don't like paying tax any more than the English.

The Scottish Tories should have cut up rough over the high speed rail link stopping at Leeds. They should be promoting, not opposing, the teaching of Scottish history in secondary schools, especially the Scottish Enlightenment, Adam Smith, and David Hume. They should be promoting financial education in schools too. And how did the Scottish Tories end up as the only party to back the restoration of university tuition fees at the Scottish Parliamentary elections? This is suicide politics from a party that is simply incapable of acting independently of Her Master's Voice in London. Look how Ms Davidson cravenly U-turned on minimum pricing of alcohol only after David Cameron had adopted the policy in England.

The Tory Party should be claiming issues such as freezing council tax. They should be supporting the devolution of the Crown Estate, a body which a Westminster committee says is behaving like an "absentee landlord" over the Scottish shoreline. They should be calling for more enterprise zones in West Central Scotland; scrapping business rates and replacing them with land value taxation – anything to address Scotland's low business start-up rate. The Tories somehow allowed the enterprise agenda to fall into the lap of the SNP.

If they persist with pusillanimous Unionism they are lost. The UK Conservatives used to be called "the stupid party", largely because of the presence of anti-intellectual knights of the shire who populated the back benches in Westminster. Well, the UK Tories got clever and started doing unnatural things like forming coalitions with the Liberal Democrats. The Scottish Tories need to brain up as well. They need to show that they are the grit in David Cameron's oyster. A nice face isn't enough.