I am mesmerised by the US presidential primaries. Not in the way that many other Washington-watchers are, reading online newspaper polls from Midwest states they couldn’t point to on a map. Instead, for me, it’s a disbelief that the first and second rules of politics seem like complete strangers to so many of the candidates. A quick recap. Rule One is: know what you’re for. Rule Two, which can be deployed alongside or (in extremis) instead of Rule One, is: have the self-respect to know what you’re against.

And yet in this contest, perhaps the last in which the US dominates a unipolar world, many candidates do not seem to know why they want to be president. Twelve Republicans and a lone Democrat have so far “suspended” their tilt at the White House. Each thought they were capable of being the 45th president and yet I can’t think of a single big idea they believed in, apart from the obligatory faith in America.

Theirs has been a past-tense vision of the future. Most wanted to have been president without knowing what they would do with their presidency. Of those left standing, the Republican crusader Ted Cruz has the clearest sense of purpose. “The Donald” hasn’t bothered to work out what he’s for but he sure as hell knows how to run a Rule Two campaign. The tenth president, John Tyler, would delight in a Trump win. No longer would he be regarded as the most abject of any and all commanders-in-chief.

Hillary Clinton and Jeb Bush, the most substantial and subtle to compete, have stumbled. That’s surprising, as the former first lady and first brother have had a decade to nuance their appeal. The Texan couldn’t decide whether he was Jeb – distinct from his father and brother – or the second sequel of a Bush trilogy. Unfairly for Hillary, there’s a sense she would be continuity Clinton after Bill, a man many believe is ill suited to being the first American first gentleman. A more stinging critique is that her pitch fluctuates between standing for her own first term and Barack Obama’s third.

None of this is a uniquely American foible. In Australia, party colleagues club their own sitting PMs into bloody submission. And with admirable but unsuccessful dexterity, Gordon Brown fought his 2010 general election campaign against both his predecessor and the man who became his successor. George Osborne will take a simpler path to No 10.

But if it’s breathtaking, eye-watering campaign chutzpah you’re after – then look to Scotland. In this May’s elections the SNP plans to be the insurgency against its own incumbency. The party will travel the country carrying an anti-austerity message of convenience in utter repudiation of its eight-year-long vapour trail in government of doing so little to support the poor.

Until May last year, I represented one of the richest constituencies in Scotland. It was next door to the area I grew up in. The two constituencies were separated by a single open field but divided by a nine-year gap in life expectancy. Every big city has these contrasts of poverty cheek-by-jowl with prosperity. I’m not standing for the US presidency, so I’ll spare you all the true but schmaltzy stories of how I slept in the bottom drawer as my brother slept two drawers above me.

While I was an MP, constituents often quizzed me on why Labour prioritised investing in the place where I grew up above the area I represented. Our pension credits, the New Deal, doubling NHS spending and tax credits were among the many measures that helped those on the other side of that field the most. But for the past nine years, under the SNP government of Alex Salmond and now Nicola Sturgeon, the investment has journeyed disproportionately in the opposite direction.

In recent times, the SNP has been a strange mix of electoral hegemony and policy timidity. It has voted against extending the Living Wage to more cleaners, caterers and carers while blocking Scottish Labour’s plans to ban rip-off rent rises. It has set income tax at the same level as George Osborne and forced councils to set council tax lower than Osborne has. The promise of the “democratic intellect” of unfettered educational fairness is now in jeopardy. Scotland has the lowest level of bursaries in western Europe and is the only nation of the UK where poorer students will borrow more than richer ones.

All the while, the SNP plans to spend ten times more on a climate-busting tax cut for airlines than it would on a poverty-challenging plan to close the gap between the richest and the rest in schools. A party that is driven by a ferocious loathing of the constitutional status quo seems intensely relaxed about the economic situation.

During the 2014 Scotland referendum, the party even tried to co-opt the NHS to its cause with its trite “NHYes” slogan. A peculiar ploy, when health spending is increasing faster in England under David Cameron than in Scotland under the SNP.

All the while, it has tried to monopolise Scotland’s flag, history and streets. The SNP seeks to conflate the party with our country, and it responds to criticism of the former with the rebuke that its detractors are hampered by an insufficient belief in the latter. And now it has embarked on the long march towards another divisive referendum. In only his second conference speech as leader of the opposition, Tony Blair said of the Tories: “It’s no good waving the fabric of our flag when you’ve spent . . . years tearing apart the fabric of our nation.” Another time and a different flag, but a Labour opposition can again make that accusation against a party of government.

While we’re at it, the SNP should also be reminded that the answer to Rule Two – know who you’re against – shouldn’t be the politician staring back at you in the mirror.