An election campaign can change in an instant — after Joe Biden's widely-panned debate performance against Donald Trump, political analysis focused on whether Biden was too old and tired at 81 to be US president.
Nobody predicted , changing the trajectory of the campaign and raising questions around the divided nature of politics in America.
Analysts are now focused on what this moment in history will mean for Trump and Biden, when voters cast their ballot in November.
How will the assassination attempt affect Trump's chances?
History shows that assassination attempts can sometimes help a candidate's political chances, Australian National University (ANU) professor of international relations Wesley Widmaier told SBS News.
Widmaier gave the example of former US president Ronald Reagan, who avoided assassination in 1981.
"Reagan was not doing terribly well and there was this groundswell of sympathy for him," Widmaier said.
"He famously joked to his doctors in the hospital, 'I hope you're all Republicans'. And so people kind of rallied around him."
Widmaier said that Trump had been comparatively "very disciplined" in this campaign, and that could mean more sympathy for him.
Trump raised his fist at supporters as he was supported off the stage by Secret Service agents, a gesture which Widmaier said could indicate Trump will attempt to portray himself as a hero.
US presidential election 'still months away'
But not everyone agrees.
US politics author John Hart, also from ANU, thinks the election will be very closely contested.
"I don't think the shooting will have a major effect and I don't even think it'll have a particularly noticeable effect in the long term," Hart told SBS News.
"American politics is so polarised and unstable as the election campaign is in turmoil at the moment because of what's happening on the other side (with the Democrats) as well.
"There's still nearly three months to go before election day."
Will Democrats switch support to Trump?
He said Biden supporters at this point won't switch their voting preference to Trump, though sympathy for Trump could sway undecided voters slightly.
In 2020, Trump was accused of encouraging a violent insurrection as some of his supporters stormed the Capitol building on 6 January.
Hart and Widmaier both said it is possible that Trump could stir up social disorder after being shot at, but that he could benefit from running a "disciplined campaign".
Donald Trump raises his fist in the air while held by secret service agents. Source: AAP
"When, sort of, mobilising really anti-Trump rhetoric could be seen through the lens of this shooting. It could be seen as an act of violence," Smith said.
"It's going to be very hard over the next few weeks for Democrats to try to build an anti-trump campaign when there's going to be a bit of a taboo against criticising Trump in really strong terms giving what's just happened to him."
Polling from Reuters conducted prior to the attack shows over 20 per cent of voters say they are undecided on their preferred president.
'Things are going to get worse'
Smith said the incident was likely to raise the stakes of the election.
"It will create the sense that this is a real us or them election and that the other side shouldn't be seen as opponents or competitors, but as a threat to America," he told SBS News.
"So unfortunately, I think that this is just going to make things worse — at least in the short term."
Smith did not discount the potential for further violence.
"This is one of the really disturbing features of this attack: the fact that it could happen at all shows that it can happen again," he said.
"It only takes a few people in a heavily-armed society to be able to inflict this kind of mayhem on the whole political system."
What have US politicians said?
US president Joe Biden condemned the attack and said Trump should have been able to conduct the rally in peace.
"There’s no place for violence in this country. It's sick," he said at a press conference.
"It is one of the reasons we have to unite this country. We cannot allow for this to be happening, we cannot be like this, we cannot condone this.
Some of Trump’s closest allies and supporters are already blaming Biden for the violence, with one Republican congressman accusing the president of "inciting an assassination" in a post on X.
Senator JD Vance, who is thought to be on the shortlist to become Trump’s vice-presidential candidate, said the rhetoric from the Biden campaign led directly to this incident.
Former Presidents Barack Obama, George W Bush, Bill Clinton and Jimmy Carter all denounced the violence and said they were relieved Trump was not hurt.
