It’s worthwhile trying to imagine what might have happened had Donald Trump been shot and killed after playing the fifth hole at his Florida golf course at the weekend. Though many people might love to see the back of an obnoxious man who incited others to violence, this weekend’s incident has prompted calls for tighter security around the former president and weighty condemnation from his rival Kamala Harris, who says she is “deeply disturbed” by the apparent assassination attempt and tweeted: “I am glad he is safe. Violence has no place in America.” Yet, with this, the second mortal threat, speculation is inevitable. And, paradoxically, Trump dead could be even more dangerous than Trump alive. Trump’s killing would be a personal tragedy – primarily for him and his family. It would mark the end of an extraordinary, tumultuous, always polarising political career. It would add his name, undeservedly, to an honoured list of assassinated US presidents that includes John F Kennedy and Abraham Lincoln. But far more than that, Trump’s death at the hands of a lone would-be sniper (as reportedly nearly happened on Sunday) would have thrown US politics and the November presidential election into utter confusion. His sudden passing would create an unprecedented, certainly unpredictable and possibly anarchic political vacuum at home and abroad. A few foreign governments – Iran comes to mind – would welcome his elimination and seek to take advantage of the ensuing uncertainty. Yet the Russian and Chinese dictators, Vladimir Putin and Xi Jinping, would not necessarily be among them. They regard Trump as a “useful idiot”, in the words of his former national security adviser, John Bolton – a shallow man easily flattered and manipulated. In any case, both Putin and Xi are understandably opposed to assassinating dictators. They’d miss him. A post-Trump world could look very different. The alleged would-be assassin in Florida reportedly held strong pro-Ukraine views and had lobbied and travelled to the country to express his support for its resistance to Russia’s illegal invasion. It’s no secret that Ukraine’s embattled government fears a second Trump term may mean the end of US military and financial assistance, and an enforced, unequal settlement with Moscow. A Kamala Harris presidency, in contrast, promises a continuation of Joe Biden’s policy of cautious support. Few would be so vulgar as to say so, but Trump’s abrupt departure might be a relief to Kyiv. Similarly, politicians across Europe, not least in Britain, might privately be pleased if hostile, xenophobic Trump were no longer around to hurl insults across the Atlantic, remind them of broken promises on defence and security – and disrupt western policy, from Gaza to the climate crisis. But it is at home that Trump’s sudden demise would most powerfully be felt. He would inevitably be cast as a martyr by his Make America Great Again followers and their media boosters. They would probably claim, as happened after July’s failed assassination attempt in Pennsylvania, that the Biden administration and the Democrats were somehow part of a plot to kill him. Even though Trump survived on Sunday, this is already happening again. Might violent disorder have ensued, had Trump died? It seems likely. The impact on a US election already upended by Biden’s late decision to quit the race would also be stupendous. There would be calls to postpone the vote. Constitutionally, that’s a tough, perhaps impossible, call. More probably, perhaps, the Republicans, like the Democrats in the summer, would turn, in extremis, to the number two on the ticket – their vice-presidential nominee, JD Vance. How scary that would be! At least Trump is a known quantity. Vance is equally “weird”, as Harris’s running mate, Tim Walz, says, but he’s a dark horse with highly objectionable views of his own, notably about women’s roles. Vance seeking the presidency, milking the sympathy vote for his late lamented master, might be an even worse nightmare for Harris. Trump’s hopefully hyperbolic vows to penalise his enemies, should he be re-elected, might ultimately appear mild in comparison with a President Vance vengefully victimising democracy itself in order to settle scores with all who oppose his hand-me-down Trumpism. For many moral and other practical reasons, it’s just as well Trump wasn’t harmed in Florida. Far preferable, and safer for the battered cause of universal democracy and human rights, to shoot him down figuratively at the ballot box. Far better for a healthy, functional society that his arguments (such as they are), his gross prejudices and wild-eyed bigotry be publicly, firmly rejected for all to see. It’s more important to discredit and extirpate this brand of evil than to destroy its chief advocate in person. Trump belongs in jail, not in the ground, and if Harris prevails in November, it’s more possible that is where he will end up. Meanwhile, the US government, the FBI, the Secret Service and the rest of the “law enforcement community” must try to ensure the reviving US penchant for political assassination does not accelerate. There are real, justified fears now for the safety not only of Trump and Vance but also for Harris, Biden and Walz – all prominent potential copycat targets in a society sick with gun violence, schism and hate. This is the wider threat highlighted by the Florida golf course drama. Russian, Iranian and North Korean hackers can do their worst. Online social media disinformation is a huge problem. So, too, is vote suppression, as is local and state-level election interference by Trump’s misguided backers. But more worrying, more frightening than all of that, is the prospect of the US’s system of representative government, still despite everything a shining example to the world, being brought to its knees by gun-toting crazies, coup plotters and the violent use of force. Trying to kill Trump amounts to much the same as trying to kill democracy. Like a rat in a trap or a toad in a hole, it’s best to keep him alive and kicking – until he is politically put down. Simon Tisdall is the Observer’s foreign affairs commentator