Any decision with the potential to nudge world history towards a different path, laden with infinite possible ramifications and the sort of unknowables that time alone can demystify, demands a sober, balanced and delicately nuanced analysis. Only a moron would risk looking an imbecile in a few months' time by rushing to judgement, and reducing all the byzantine complexities to a bunch of childishly simplistic rhetorical questions.

And so, with that magnificently pompous thought in mind, we ask this regarding Mitt Romney's choice of Paul Ryan as his running mate. Is Mittens raving bloody mad? Is he a Democratic sleeper who buried himself in the GOP establishment purely to guarantee Barack Obama's re-election? Or is he, for all the outsourcing and asset-stripping commercial smarts that built his $250m fortune, a dunce?

The alternative is, as Adrian Hamilton noted in this paper on Monday, too mortifying to contemplate. If Ryan, the personable young congressman from Wisconsin with the meisterplan to dismantle the welfare state, proves the alchemist Romney hopes him to be, and mutates his leaden campaign into electoral gold, stand by for a neat reversal of the old Marxist saw about the repetitive pattern of history. Where Sarah Palin brought high farce to the last-roll-of-the-dice, game-changing Republican vice-presidential pick, were Mr Ryan to propel this ticket to the White House it would be an American tragedy.

Unlike Palin, Mr Ryan is not spectacularly uncurious and ignorant. Apart from grasping that the Queen does not moonlight as our prime minister, he is an intelligent, rather wonkish though unrobotic politico-economic philosopher. Broadly speaking, the philosophy to which he has now shackled Romney is that of Ayn Rand.

There is a paradox in Mr Ryan's worship of that laureate of desiccated social Darwinism – the faith that the economically weak must be left to the tender mercies of the human jungle's fittest and wealthiest survivors. Where Rand, whose books Ryan presses upon his staff, was a pro-choice atheist, he is an observant Catholic who would outlaw abortions for the victims of rape and incest.

In other regards, he established himself as Rand's spiritual son with the budget – unsurprisingly rejected by the Democrat-controlled Senate – that he presented to Congress. The gist of this remarkable document, already described by one commentator as the most heavily annotated political suicide note in history, was further cutting taxes for the plutocratic likes of Romney by effectively raising tax on medium earners, slashing public spending on Medicare (the healthcare subsidy for the elderly and disabled), privatising social security (you can guess where that leads), and denying loans to those otherwise unable to send their children to college.

Hard as it is for even conservative-minded Europeans to comprehend how a chunk of a nation so given to ostentatious religiosity could embrace such vicious amorality, it is a vaguely consistent intellectual standpoint. Economically, it may not make sense: independent analysts insist that the Ryan budget would reduce the deficit more slowly than currently envisaged. Romney may wish to frame this election as a fork-in-the-road choice about tackling that deficit, but that is a distraction. The true battle is an ideological one between the belief that in any civilised society the rich should help the needy via the ministrations of the state; and the rival tenet that, in so far as there is any such thing as society at all, it is best ordered by deploying the state to increase the wealth of the wealthy at the expense of the struggling.

If the brilliance of modern Republican politics, as enabled by such as Rupert Murdoch who tweetfully celebrated Ryan's appointment as "almost perfect", has been to coax the poor into voting against their own interests, behold its ultimate test. Can the millions of old-timers in Florida, without whom it is virtually impossible for Romney to win, be persuaded to endorse the destruction of the Medicare on which they depend? Will independents vote for a ticket determined to deny their children higher education? Is it conceivable that the unemployed in swing states will be seduced by the prospect of an already flimsy welfare net being lacerated?

With his uncanny prediction that the British would be indifferent to the Olympics so fresh in the memory, it would of course be folly to disregard Romney's gift for prescience. If Murdoch and Bill Kristol, the Mr Wrong of uber-right US journalism who did so much to foist Palin on John McCain, are convinced that Ryan is the Jesus to Romney's Lazarus, then who are bemused observers from across the ocean to doubt their soothsaying? Whatever orthodoxy holds about elections being won from the centre, perhaps the most eye-poppingly, mouth-foamingly distempered right-wing extreme of the spectrum is the best ground from which to take down as canny a pragmatic centrist as Obama. If so, God have mercy on America – and also, considering the tendency of American trends to cross the Atlantic, on us.