The spectacle that is the American presidential nominating process was portrayed in sharp relief when volatile tycoon Donald Trump was formally anointed as the choice of the Republican Party at a glitzy event last week. The glamour and clamour befitted a rock star rather than a sagacious leader who could helm the most powerful nation in the world. Mr Trump's supporters were held agog, while many around the world looked on aghast. That contrast in opposing responses was less stark at the Democratic national convention at which establishment candidate Hillary Clinton was nominated, but the unease remained. At its root is the incredulity with which the presidential race is viewed by the outside world - partly because the nomination process is numbingly costly, complex, competitive and circuitous.

For all that, it has yielded two candidates who have not inspired overwhelming confidence, even among party heavyweights in the case of the Republicans. A Trump presidency is worrying as a leader with "poor self-control and (a) flawed temperament", in the eyes of The Economist magazine, would be the one with his finger on the nuclear button. Whereas, a commander-in-chief who is regarded as not honest and trustworthy - as Mrs Clinton is seen by 68 per cent of Americans polled by CNN/Opinion Research Corporation - is also problematic. That figure could well be higher as Mrs Clinton lied blatantly about not having "any material that was marked classified" go through her private server in breach of national security, when in fact there were 110 such e-mails, some marked "top secret". Ironically, Mr Trump is perceived as being honest and trustworthy by 43 per cent of voters even though he is "so cavalier about the facts", as The Washington Post observed.

What could account for the disconnect between perception and reality in the United States? Some, like current affairs website Salon, blame it on the shallowness of American consumer and media culture which is "now intertwined with our political culture". Mr Trump taps into the frustrations of a large segment of voters and offers them a message that's "appealing in its simplicity, but there's nothing behind it". That's a peril all democratic nations face, as seen in the Philippines where a foul-mouthed and extremist pitch swept President Rodrigo Duterte into power.

Another danger is the harmful divisiveness of a political culture which paralyses legislation and can even bring the US government to a standstill. That was in full swing at the Republican national convention where much time was spent attacking the Democrats, rather than shedding light on pressing issues facing the nation. Alas, the flawed process of picking the world's pre-eminent leader might put "a thriving country at risk of a great, self-inflicted wound", as a British observer noted. The effects of that would be felt by the world, too.