ANDREW NEIL: If Donald Trump can rise to this occasion, he’ll be truly unstoppable. But the danger is he succumbs to anger…

Europe’s leaders woke up yesterday morning to a prospect that most of them find terrifying and would rather not think about: Donald Trump as the next president of the United States.

They must now prepare for turmoil over US support for Ukraine, support for NATO, punitive tariffs on their exports to the US, and whatever surprises the unpredictable Trump has in store that he hasn’t told us about yet.

The election was already going in Trump’s favor, because every public appearance by an uncertain, confused President Biden only confirmed what most Americans had already concluded: that he was unfit to run for re-election. And the Democrats had no backbone when it came to taking action against it.

But the failed assassination attempt Saturday night at a Trump rally in Pennsylvania makes a victory for The Donald more likely than ever.

Trump had blood streaming down his cheeks as Secret Service agents pushed him to the ground

A number of American friends and sources contacted me during the night to say that they thought Trump would now win by a landslide. And these were not his supporters – they were all Democrats or ‘Never Trump’ Republicans.

Team Biden planned to make liberal use of the famous photo of Trump taken in a Georgia prison last August after he was charged with racketeering, among other things, during the campaign. At the same time, they wanted to remind everyone that he was already a convicted felon.

I remember writing something at the time that this would be the defining image of the 2024 presidential election.

No longer. That accolade now goes to Trump, who stands with his fist in the air, blood splattered across his face, screaming “Fight, fight, fight” as the Secret Service shoved him off the stage after he was within an inch of death. There was even a giant American flag flying in the background.

For Trump and his MAGA (Make America Great Again) movement, this will now become the totemic image of his candidacy. It will remind his true believers of the iconic image of US Marines planting a giant flag on a hilltop after the brutal battle for the island of Iwo Jima from the Japanese in early 1945.

But that famous photo contained an element of staging (a smaller flag had previously been raised on the site). Trump’s powerful photo is completely authentic. No one can dismiss it as fake news.

The core theme of the Biden campaign, heavily promoted by its many cheerleaders in the media, is that Trump is an existential threat to democracy. It is emblematic of the overheated rhetoric dominating debate on both sides of the political divide in America these days.

But it will be a lot harder to use that argument credibly against a political candidate who nearly lost his life campaigning in a democratic battle.

The shooting (which, let’s not forget, left one person dead and two seriously injured) has led to predictable calls for the US to curb its hateful and hostile political discourse, much as the killing of Labour MP Jo Cox during the 2016 Brexit referendum led to calls for a more civilised debate in our politics.

I suspect that such calls will be even less successful in America than they have been in Britain.

President Biden and his Democratic predecessor in the White House, Barack Obama, were quick to condemn “political violence,” though their remarks were perfunctory and devoid of genuine outrage. Oddly, neither could bring themselves to use the words that would have accurately described what had happened: attempted murder.

Instead of calming the situation, America is already being awash with insane conspiracy theories, fueled by the incompetence of those tasked with protecting Trump when they allowed a 20-year-old with a semi-automatic rifle onto a rooftop overlooking the rally.

The shooting has led to predictable calls for America to curb its hateful and hostile political discourse, writes ANDREW NEIL

The Secret Service’s chaotic efforts to evacuate Trump after the shooting only contributed to the loss of trust

Their incompetence was highlighted in a remarkable BBC TV interview carried by US broadcast networks, in which a witness said he had warned police and security officials that a gunman was on a nearby roof. The Secret Service’s chaotic attempts to evacuate Trump after the shooting only added to the loss of confidence.

Conspiracy theorists see this as evidence that it was all a deep state effort involving the FBI and Secret Service to get rid of Trump (the MAGA camp’s view) or that it was all staged by MAGA agents to boost Trump’s chances in the election (the crazed left wing view).

Such nonsense deserves no time. But the Secret Service and its law enforcement agencies are facing a terrible reckoning. There are already calls for the director to resign.

Biden will be relieved that his ineligibility to run again is no longer dominating the headlines. But it is a temporary relief. The pressure to find a candidate who can beat Trump is more urgent than ever, though he may now be untouchable no matter who the Democrats field as their nominee.

Some Democratic hopefuls may find it wiser to skip this particular presidential election cycle. After Saturday night, Democrats appear to be out of good choices.

And the clock is ticking. The Democratic convention is just five weeks away and, unless the “Dump Biden” rebels act quickly in the next 10 days, they will run out of time to make the necessary arrangements to turn Chicago into an “open convention” parade of alternative candidates.

Police stand by the body of alleged shooter Thomas Matthews Crooks

Biden would simply be confirmed as the nominee by default, since most of the delegates have been pledged to him and can only be released if he withdraws. A few days ago, Biden said, “It’s time to hit Trump in the bull’s-eye,” confirming that his capacity for blunders is unlimited.

As leaders of America’s allies — and enemies — grapple with the implications of a Trump presidency, all eyes are on the Republican National Convention tomorrow in Milwaukee.

It was always going to be an uncontested coronation for Trump. Now it will be an emotionally charged, historic event designed to propel him relentlessly into the White House and into the sights not just of America, but of the world.

In 1984 I was in the hotel next door to the Grand in Brighton for the Conservative Party annual conference on the night the IRA blew up the hotel in a failed attempt to assassinate Margaret Thatcher.

She insisted on being the first to speak at the conference that morning, even though she had nearly been killed and had to be evacuated to a safe base in the middle of the night.

By the time we gathered in the conference room we had been joined by all the London correspondents from the world media. The Iron Lady arrived in time to a sober but warm and sincere reception.

She spoke with calm authority, no bitterness, no drumbeat, just an unwavering determination to defend democracy. It was the speech of the leader of a proud nation, not the leader of a party.

If Trump can seize the opportunity in Milwaukee in the same way, he will be truly unstoppable in November. If he succumbs to anger, stokes divisions and makes ridiculous accusations against Democrats, he may still be vulnerable.

In 1912, another presidential candidate, Teddy Roosevelt, spoke in Milwaukee. Like Trump, he had barely begun his campaign speech when he too was the target of an assassin’s bullet, which lodged in his chest. But Roosevelt was a tough guy—he once boasted that he felt as strong as a moose—and decided to finish his 84-minute speech.

Like Trump, Roosevelt was already a Republican president. But he now led a secessionist party called, appropriately enough, the Bull Moose Party. Third parties never win in America. Trump’s test this week is a little less severe.

The bullet only grazed his right ear and he still leads the Republicans. It seems that only his own dark demons can stop him from becoming the next President of the United States.

So far, he has remained remarkably subdued since the shooting, and he must continue to do so for the sake of his adoring, loyal fans in Milwaukee, for whom he is now a living MAGA martyr.