There is a storied and bloody history of US presidential assassination attempts, and Donald Trump on Saturday joined a long list of former holders of the office who were threatened with violence, wounded or died as a result.
Four presidents were assassinated – Abraham Lincoln, James A Garfield, William McKinley and John F Kennedy.
Three more, including Trump, were injured in attacks.
Before Trump, in March 1981,Ronald Reagan was the last US president to have been injured in an assassination attempt.
He was shot outside a hotel in Washington DC shortly after taking office.
Reagan was wounded when one of the several bullets fired ricocheted off of the limousine, striking him under the left armpit.
Shooter John Hinckley Jr, a fantasist, later said that he believed his attempt would impress young actress Jodie Foster, with whom he was infatuated with from her role as a child prostitute in Taxi Driver, ironically a film portraying a political assassination attempt.
Reagan responded, as he did to so many things, by cracking a joke.
Before he went into surgery to remove a bullet lodged near his heart, he said to his wife Nancy: “Honey, I forgot to duck.”
Years later, realising what sounded like a gunshot at the Republican National Convention was actually a balloon popping, he remarked: “You missed me.”
The American public loved Reagan’s gift for humour, and his approval rating soared in the aftermath of the attack – helped in no small part by weeks of coverage focusing on the attack and his recovery.
It also had direct policy implications. In the immediate aftermath of the attack, Reagan’s daughter Maureen called for tighter gun control laws.
Reagan did not push the issue hard as president. But on the 10th anniversary of the attack, after he had retired, he wrote in The New York Times that “this nightmare might never have happened” if a bill to enforce background checks on owners of handguns then before congress had been in place.
The Brady Act, named after White House secretary Jim Brady, who was shot in the head and paralysed in the attack, finally passed by Congress and signed into law by Bill Clinton in 1993.
Trump is not a natural joker like Reagan was, but he is also likely to enjoy a polls bounce from the next few weeks of coverage of the attack, his own recovery and the heroism or possible blunders of the Secret Service, which will dominate the media reporting.
A Republican candidate backing current or new gun controls seems unthinkable in today’s political climate in America.
But campaigners have long called for restrictions on the kind of AR-15 type rifle his would be assassin was using.
If he were to win the White House in November and were so minded, Trump would probably have a unique opportunity to push such legislation through.
Reagan and Trump were lucky: both dodged death by millimetres.
Other presidents have not been so fortunate.
In perhaps the most famous assassination of all time, John F Kennedy was shot by Lee Harvey Oswald while travelling through Dallas, Texas, in an open-topped car with his wife Jackie in 1963.
Like Trump, Kennedy was targeted by a sniper.
But Oswald, a former US marine, did not miss: the president was struck by two bullets in the head and back, and pronounced dead half an hour later at a nearby hospital.
Kennedy’s assassination had a lasting impact on American culture, with the “grassy knoll” phenomenon taking hold in the popular psyche.
Although an official investigation found that Oswald acted alone, a poll last year found that a majority of Americans believe he was part of a wider conspiracy.
In June 5 1968, JFK’s brother Robert, a would-be president, was killed when he was shot by Jack Ruby at the Ambassador hotel in Los Angeles.
Abraham Lincoln, whose assassination at Ford’s Theatre in Washington DC on April 14 1865 is one of the most famous stories in American political history.
Lincoln was killed by John Wilkes Booth, an actor and supporter of the Confederacy who was incensed with the then-president’s suggestion that voting rights should be extended to black Americans.
James A Garfield was shot in a railway station in Washington DC on July 2 1881 by a disturbed man called Charles J Guiteau who was angry at not having been appointed ambassador to France.
He died 11 weeks later from an infection.
Two decades later, Republican president William McKinley was shot in the stomach at a fair in New York state on Sept 6 1901 by anarchist Leon Czolgosz. The president died eight days later from gangrene.
After McKinley’s death, the Secret Service was directed to begin round-the-clock security for sitting presidents.
George HW Bush was the subject of an assassination plot by a group of Kuwaiti and Iraqi assailants believed to have been working for Saddam Hussein, the Iraqi dictator.
They intended to kill him in January 1993, after he had left office, with a car bomb.
Bill Clinton, Bush’s successor, launched a missile at an Iraqi intelligence installation in response to the unsuccessful plot.
A subsequent investigation by the CIA ruled that the plot may have been invented by Kuwaiti officials.
At least five people have attempted to kill Mr Clinton, including with a pipe bomb addressed to his wife, Hillary, and by firing long-distance rounds at the White House.
George W Bush was the target of an assassination plot in May 2022, when an Iraqi citizen was arrested for putting together a team of IS sympathisers to kill the architect of the War on Terror.
He said the plot was motivated by anger about the Iraq war.
Barack Obama, America’s first black president, was the target of several assassination plots by white supremacists and far-Right groups.
In 2013, an Elvis impersonator from Mississippi was arrested after letters laced with the poison ricin were sent to Mr Obama, but was later released after police admitted he had nothing to do with the case.
He later said: “I don’t even like rice.”
US actress Shannon Guess Richardson got 18 years in prison for sending the letters to Mr Obama, then-New York mayor Michael Bloomberg and a gun control activist.
Oscar Ramiro Ortega-Hernandez, a 21-year-old conspiracy theorist, was sentenced to 25 years in prison in 2011 for firing rounds at the White House that were intended to kill Mr Obama.
In May 2023, when Joe Biden was president, a 19-year-old man was arrested after driving a rented van into a White House barrier.
He later said that he was a Nazi sympathiser and was prepared to “kill the president” and “seize power”.
He pleaded guilty to a charge of destroying federal property and faces 10 years in prison. He has not yet been sentenced.
In August 2023, a man who threatened to assassinate Mr Biden in Utah was shot dead by the FBI hours before the president arrived in the state.
Craig Deleeuw Robertson, 75, died when special agents raided his home to arrest him in Provo, a city south of Salt Lake City.
Trump has faced several attempts on his life, including in an incident at a rally for his 2016 presidential campaign in Paradise, Nevada, when Briton Michael Sandford attempted to grab the gun of a police officer providing security for the event.
Sandford claimed that he had wished to kill Trump to prevent him from becoming president. He got a year in jail but was released and deported to the UK after 11 months in custody.
Hard questions are already being asked about security in Butler, Pennsylvania, on Saturday.
Trump, like Reagan, will probably benefit politically from being at the centre of the next few weeks’ media coverage and the natural sympathy of voters for someone who has survived an attempted murder.
And in the radically polarised atmosphere of contemporary America, it would be surprising if conspiracy theories do not being to spread – no matter how well the true course of events is established.
Wilkes Booth and Czolgosz had political motives.
But the men who attacked Garfield and Reagan were delusional. Lee Harvey Oswald’s case remains a hotly debated mystery.
With that in mind, it is too early to say what exactly motivated the man who tried to kill Trump.