Former president Donald Trump has again crushed Nikki Haley, his former ambassador to the United Nations, and this time in her home state of South Carolina where she served two terms as governor. It was an especially humiliating defeat.

Trump the triumphant now appears to be on an unstoppable glide path to his coronation for the third successive time as the Republican presidential nominee. He has driven a dozen contenders from the race, purged the Republican Party of its leadership and installed his own generals (including his daughter-in-law Laura Trump) with iron-grip control over the party and its funding.

Trump has played the new Republican Speaker of the House of Representatives, Mike Johnson, for his puppet by directing Johnson not to bring the Ukraine aid bill and tougher immigration laws to the floor for a vote – where it would almost surely pass – and has used his allies to tell Johnson: you bring up Ukraine and we will remove you from office.

Trump looks stronger, and President Joe Biden looks weaker, than at any time over the course of Biden’s term. Trump has a higher favourability rating (43.7 per cent) to Biden’s (39.6 per cent), and lower unfavourable numbers (Trump 51.9 per cent unfavourable, Biden 55.6 per cent). The Republican Party is firmly united behind Trump. But Biden cannot escape his 81 years, with media speculation rampant that Biden should step aside and let another dynamic leader carry the party forward to victory in November. The angst is prevalent, but Biden is not leaving the field.

Biden cannot win in November from where he is right now. He must work to get his approval rating to 45 per cent or more. But Trump also cannot win from where he is right now. The pressing question is not about Biden, who has room to strengthen by attacking Trump’s extremism and authoritarian character, but about Trump. Has Trump peaked? Is this as good as it gets for him?

We will not know the answer until November, but the entrails from the Republican primaries so far indicate that Trump is falling short. In Iowa, Trump won 51 per cent of the caucus vote. DeSantis and Hayley together polled 40 per cent. In New Hampshire, Trump won 54 per cent from Republican voters; Haley was at 43 per cent. In South Carolina last weekend, Trump won 60 per cent. Haley was just shy of 40 per cent.

Yes, Trump conquered. But these three contests, in different parts of the country, show that 35-40 per cent of Republicans voting did not support Trump. Many of them may not in November. Fox Newsfound that 35 per cent of New Hampshire voters were dissatisfied with Trump and would not vote for him in November. Fifteen per cent of Iowa caucus voters said the same.

Nikki Hayley, looking like Rocky Balboa but without a comeback in store, is staying in the ring for a few more rounds. She is pounding away with the gloves off. She calls into question Trump’s competence, his unfitness for office, and his cognitive abilities and speech infirmities. Haley is attacking Trump on his track record of losing Republican control of the House and Senate and the White House, on denigrating those serving in the armed forces (including her husband), on running up the national debt by $US8 trillion ($12 trillion) in his first term.

Most importantly, Haley is skewering Trump for his siding with Putin on Ukraine and NATO. Indeed, Trump’s declaration that Russia could do “whatever the hell it wanted to” was a cut-through moment for not only Americans but world leaders on where Trump stands on Russia. The only thing Trump could say about the murder of Alexei Navalny is that there is a parallel with how Trump is treated in the US by Biden and the radical Democrats.

Haley continues to highlight the legal assaults on Trump’s reputation. His conviction in New York for fraudulent business practices means much more than the $US500 million in penalties and interest he faces (plus another $US90 million for defamation against a woman he sexually assaulted). Trump’s image of being the master CEO of all time was trashed by the court’s barring him from running his companies for three years. Trump’s dream run with voters from his days with The Apprentice is long gone.

Later in March, Trump’s trial over hush money payments to Stormy Daniels will again bring his tabloid behaviour to the front pages. Trump desperately wants – he urgently needs – an acquittal in this case, which is seen as the weakest of all the prosecutions he is facing, to cement his charge that he is being persecuted for the sole political purpose of driving him off the ballot. But so far, Trump has struck out in every New York courtroom.

Depending on further legal proceedings, Trump may well face trial in Washington before November for his attempts to overturn the 2016 election. Over 30 per cent of Republican voters in Iowa, New Hampshire and South Carolina say they cannot vote for Trump if he is a convicted felon on election day.

By the end of March, Trump will sweep the remaining primaries and lock in the delegates needed to formally be declared the nominee when the Republican National Convention meets in July. But will Trump be more popular by then? Is this Trump’s apogee? Will a capped-out Trump lose to an unpopular Joe Biden? That is exactly what Haley said on Saturday night in South Carolina, and what she will keep saying until the bitter end: “Donald Trump cannot win a general election.”