There's a good reason that potential US first lady Melania Trump's plagiarism scandal became one of the defining moments of the Republic National Convention now concluding in Cleveland: original thought of any nature has been in critically short supply throughout the four-day event.

Were it not for Ted Cruz's party-crashing turn to exhort Republicans to 'vote your conscience' in November — thus recognising an attribute in others that many accuse him of lacking — Melania's Michelle Obama-cribbing sentiments might have left the only lasting impression from the entire RNC.

Of course, the Republican presidential candidate himself has the chance to change all that when he appears on stage to accept the party's nomination today, in what many members of the GOP establishment might be hoping is a complete departure from rhetoric-heavy but details-light performances to date.

It's far too late in the game to expect Donald Trump to abandon his nativist and Republican sacred cow-slaughtering platform, but it also far beyond time that he started injecting some more policy into his politics to try to convince the doubters that his platform might actually be workable.

Questions such as how exactly Trump intends to  wind back the forces of globalisation at the same time as many American jobs are starting to be lost to technological change sorely need to be answered if he is to have any chance of defeating Hillary Clinton later this year. Despite polls showing relatively equal support for the two candidates, the New York Times this week put Clinton's actual chances of winning the White House — taking into account state voting histories and the vagaries of the electoral college system — at 76%.

Despite those odds and the party divisions wrought by Trump, deepened by Cruz, the RNC has not descended into the chaos predicted by many commentators ahead of the event. There has indeed been a surprising spirit of unity and optimism among many previously opposed to Trump. This was best displayed by Speaker of the House Paul Ryan, whose impressively enthusiastic presentation called for unity and heralded the power of the Republicans' 'ideas'.

Yet Ryan was still typical of most speakers at the RNC in failing to properly articulate and promote these ideas. Instead he attacked Barack Obama and Clinton. Indeed, Trump's Democratic opponent has often appeared to be the true centre of attention in Cleveland, whether as the target of speakers such as New Jersey Governor Chris Christie (widely believed to be making a case for Attorney-General in a Trump administration), or the subject of 'Hillary for prison' chanting among wide sections of the audience. Then there's the overtly misogynistic merchandise being sported everywhere, and a lengthy segment of the convention program being turned over to the long-exhausted Benghazi controversy.

Aside from Clinton, much of the focus has also been on other supposed enemies of the real America, such as the Black Lives Matter movement, which attracted most attention from former New York mayor Rudy Giuliani and seems to have, at least momentarily, seen African Americans regain their role from Mexicans of favoured bogeyman of the largely white US conservative population.

While ad hominem and 'us vs them' politics have long been par for the course in America and beyond, the negative tone in Cleveland feels more compensatory than it does calculated. It appears a direct result of the schism between Trump and the mainstream Republicans, as well as the distinct lack of aptitude for, and interest in, traditional campaigning and political leadership from the nominee.

Trump has proven himself a highly effective enemy of the GOP establishment, so much so that most of its members have been chastened into falling in behind him. But it is not for the likes of Ryan to unite the party behind ideas, because he represents a line of thinking that has been firmly rejected by the majority of GOP voters.

Regardless of what he says on the Quicken Loans Arena stage today or in the weeks and months ahead, Trump surely has a lock on the white working class Republic voting bloc, while much of the doctrinaire free market, small government crowd seems to have reluctantly signed on out of a sense of loyalty or merely a greater dislike of his opponent. Yet, alongside Cruz are some major holdouts that may significantly affect the enthusiasm of conservatives to turn out for him — multibillionaire financers and major architects of the contemporary GOP Charles and David Koch are notable among them.

This is to say nothing of independents or even Democrats for whom the promise of jobs returning to depressed areas of the country might matter more than any larger ideological or moral concerns. Trump may have previously claimed to have 'the best words', but without any connection to reality, or a still significant segment of his party, they may only carry him so far.