In the immediate aftermath of an assassination attempt against Donald Trump during a campaign rally, conspiracies have filled the vacuum left by a lack of information.

At this point, there is little understanding of the shooter’s motives and it would be irresponsible to rush to judgement. There is evidence the shooter, Thomas Matthew Crooks, had given $15 when he was 17 to a group that raises funds for Democratic party causes. When he turned 18 he registered as a Republican.

Reports from classmates said he had outspoken conservative views. According to the FBI, there was no evidence of violent rhetoric on his social media accounts, and they are still trying to work out the shooter’s motive.

This absence of evidence hasn’t stopped partisan figures making irresponsible claims that the shooter was radicalised by President Joe Biden, the Democrats, and the news media. Senator JD Vance, a Republican from Ohio, since named Trump’s vice presidential candidate, posted on X:

Also on X, Representative Marjorie Taylor Greene, a Republican from Georgia, framed the death of a rally attendee as someone “murdered at the hands of Democrat [sic] political violence.” Representative Steve Scalise, a Republican from Louisiana, issued a statement claiming this is another example of “far left lunatics” acting on “violent rhetoric”.

Scholars like Jonathan Turley argue, “We are living through an age of rage. It is not our first, but it may be the most dangerous such period in our history.”

He asserts the Trump assassination attempt was an unsurprising outcome of the political rhetoric today, and says both Democrats and Republicans are culpable. That is a strong claim given the shooter’s motive remains a mystery. But it is worthwhile examining the factors that give rise to political violence and the role of political rhetoric in legitimising violent extremism.

Toxic language is normalised

The foundation of the social contract tradition in Western democracies is that we renounce the right to resolve differences through violent means.

In a democracy, we accept vigorous debate and the exchange of different ideas. That debate occurs between groups with different interests. Historically, political parties emerge through organisation as a means of representing those interests.

Different groups can compromise on their interests. They may get part of what they want, and “win” sometimes while “losing” at other times. But it is much harder to compromise on fundamental elements of one’s identity without losing part of oneself. This sets the stage for a different kind of political competition that is unyielding to compromise – and where violence can become legitimised.

If Turley is right that both Republicans and Democrats are equally responsible for creating a situation where compromise is impossible and violence is seen as permissible, then we should expect each campaign to cast issues as uncompromising matters of identity with equally hostile legitmisations of violence.

We can analyse these claims looking at what the campaigns themselves say. Looking at the Meta Advertising library’s archive of Trump and Biden campaign ads since May 1 2024, we can assess the levels of toxicity and appeals to identity in the posts they create and pay to promote. There were 242 sentences in 1,339 Trump ads that mentioned Biden directly. Biden mentioned Trump 2,604 sentences contained in 5,722 ads his campaign ran. Levels of toxicity and hostile identity were calculated using the Perspective API, a machine learning algorithm developed by Google’s Jigsaw Project to detect levels toxic, threatening, and harmful content in online comments. Trump’s ads include slightly higher levels of identity attacks in sentences mentioning Biden, and these sentences are more than three times as toxic.

Biden’s most toxic line about Trump is, “Donald Trump is a convicted criminal who is only out for himself”, which scores a 0.57 on the toxicity scale.

One may quibble about whether Trump is technically only guilty on 34 felony counts until the judge formally enters the conviction at sentencing.

However, the political import remains that Trump was found guilty by a jury of his peers of felonies related to filing fraudulent business records to conceal illegal campaign donations when he was first elected.

Scoring as nearly as toxic is this sentence from Biden: “Donald Trump has a long history of racism and pandering to white supremacists.”

This is directly an attack on Trump himself rather than an out-group, although, indirectly, there is an attack on white supremacists. But even people who might be categorised as “white supremacists” normally do not identify as such, and there is no call for violence.

Trump’s most toxic line about Biden is: “Joe Biden’s mind is gone, and his Communist Deep State goons are driving America off a cliff.”

This statement is literally incoherent.“Communism”, spelled with a capital C, refers to an era of historical evolution in the work of Marx and Engels where the state “withers away” without any system of organised repression over the people. Communism, however unrealistic it may be, precludes the possibility of “Deep State goons” with hidden machinations.

Biden would have also made a “Deep State” driven by a political agenda more difficult to create given he rescinded Trump’s Schedule F reclassification of large parts of the public service from merit-based to political appointee roles at the start of his term.

But here there is a collective identity invoked about an unstated image of America supposedly driven off a cliff.

Political language needs to cool down, immediately

Ambiguous language with little tether to reality is a common tactic of propagandists as its layers of contradiction confound clear refutations. This phrasing implies a threat to an in-group – an element of Trump’s messaging that has figured since the 2016 campaign.

Although there is no direct appeal to violence in these ads, he has made comments that place violence on the table, claiming that there will be a “bloodbath” if he loses the election.

And the head of the Conservative Heritage Foundation, which developed Project 2025 in collaboration with Trump campaign staffers, stated their agenda will be to usher in a “second American Revolution”, which will “remain bloodless if the left allows it to be”.

This does not appear to be a case where both sides are equally responsible for the raising the prospects of political violence. Trump and his supporters couch the election as a referendum on an uncompromisible cultural battle where violence may be required.

Biden’s rhetoric does not turn on an in-group/out-group differentiation and neither he nor his surrogates speak of violence as a legitimate means to achieve a political result. If something good comes of this tragedy, which has claimed the life of one person, we can hope it involves all sides taking renewed responsibility for their rhetoric.

Michael Jensen, Associate professor, Institute for Governance and Policy Analysis, University of Canberra, University of Canberra. Republished from The Conversation.