Donald Trump and Joe Biden have both stressed "unity" in the wake of the stunning assassination attempt on the Republican presidential contender, but any shift to a more civil political discourse is likely to be short-lived.
For months, the two campaigns have shredded the other's candidate with a ferocity that exceeds the already bruising nature of US political races, and observers say there is little chance of that dynamic being altered in any significant way.
In the immediate aftermath of the shooting at a Trump rally in Pennsylvania on Saturday, both men struck a moderate tone and avoided language that could escalate the febrile political atmosphere.
Biden called on Americans to "lower the temperature" in an address from the Oval Office, and Trump said it was "more important than ever that we stand united."
The two men even spoke to each other on the phone -- after refusing to so much as shake hands at their televised debate last month.
"In the immediate aftermath of a national tragedy or a near-tragedy, politicians want to appear empathetic and say the kinds of healing things people want to hear," Roy Gutterman, an expert in communications law at Syracuse University, told AFP.
"I am sure it will not take long for the vitriol to start flowing" again, he added.
- Mockery and insult -
Trump has always favored an extremely aggressive stance towards political opponents, whom he has collectively described as "vermin."
His personal attacks on Biden have ranged from theatrically mocking the president's stammer to labeling him a "mental catastrophe."
Biden for his part refused to even mention Trump by name earlier in the race, and in recent months the president and his campaign have sharpened and personalized their messaging about Trump as an "unhinged" would-be dictator with the "morals of an alley cat."
Their June 27 debate, meanwhile, descended into an argument about who was the worst president in US history.
"I am hopeful, if skeptical, that political rhetoric in the US will get less hateful and driven by rage," Peter Loge, director of George Washington University's School of Media and Public Affairs, told AFP.
"That American politics has often been awful doesn't mean it needs to always be awful."
In an interview with NBC on Monday, Biden admitted it was a mistake to call for Trump to be put in the "bullseye" days before the assassination attempt, but he defended his repeated warnings that the former president poses an existential threat to American democracy
That line of attack is one his campaign has identified as resonating with key independent voters, and it is not one they are likely to drop or moderate.
The same day, after Trump formally won the Republican nomination at his party's convention, Biden's campaign blasted his newly unveiled running mate J.D. Vance as a "far-right MAGA extremist."
Trump meanwhile posted a message on his Truth Social platform accusing Biden of conducting an "elections interference conspiracy" and weaponizing the justice system against his political enemies.
- 'Loudest voices' -
"Extremists on both sides of the political spectrum seem to have the loudest voices these days," Gutterman said.
"They probably do not spend too much time weighing on a more moderate voice of reason or calls for peace or moderation."
As the race to the White House heats up, political pundits have called on both campaigns to tone down the rhetoric -- while urging the media to hold them accountable if they cross the line.
"The media needs to treat political violence as abnormal and destructive," Loge said.
"One way to do that is to call out all of the politicians who told everyone to calm down yesterday, and who start shouting tomorrow."
