Vice President J D Vance has jumped onto the conservative movement demanding consequences for those who have cheered Charlie Kirk's killing, calling on the public to turn in anyone who says distasteful things about the assassination of his friend and political ally.

“When you see someone celebrating Charlie’s murder, call them out,” Vance urged listeners on the slain activist’s podcast Monday. “And hell, call their employer.”

Vance's call also included a vow to target some of the biggest funders of liberal causes as conservatives stepped up their targeting of private individuals for their comments about the killing. It marked an escalation in a campaign that some warned invoked some of the darkest chapters of American history.

“The government involvement in this does inch this closer to looking like McCarthyism,” said Adam Goldstein of the Foundation for Individual Rights and Expression, referring to the 1950s campaign to root out communists that led to false allegations and ruined careers. “It was not a shining moment for free expression.”

Republican-controlled states such as Florida, Oklahoma and Texas have launched investigations of teachers accused of inappropriate statements after last week’s assassination. The US military has invited the public to report those who “celebrate or mock” the killing and said some troops have already been removed for comments.

At the same time, the Trump administration has vowed to target what it contends is a “vast” liberal network that inspired the shooter, even as authorities maintain it appears he acted alone and the investigation is ongoing.

The campaign has broadened to include even those whose statements were critical of Kirk without celebrating his assassination.

The Washington Post fired Karen Attiah, an opinion columnist, for posts on the day of the shooting that lamented how “white America” was not ready to solve gun violence and that quoted Kirk denigrating the intelligence of prominent Black women such as Michelle Obama.

PEN America, a press freedom group, warned in a statement that firings like Attiah's “risk creating a chilling effect”.

Goldstein worried there were many cases of people targeted for simply quoting Kirk or failing to mourn his passing adequately. “That’s one of the key symptoms of cancel culture,” he said. “Trying to paint everyone with the same brush.”

Conservatives coined the term cancel culture for what they claimed was persecution of those on the right for their views, especially related to the Covid-19 pandemic and January 6, 2021, attack on the US Capitol, leading to campaigns to get regular people fired.

It was a significant cause for President Donald Trump, who pledged to end it during his campaign last year. But after the Kirk killing, he and his administration have instead leaned into it from the right.

On Monday, Vance was joined on Kirk’s podcast by Stephen Miller, Trump’s deputy chief of staff, who vowed to crack down on what he called the “vast domestic terrorist network” he blamed for Kirk’s death.

Alluding to free speech concerns, Vance said: “You have the crazies on the far left that say, ’Oh, Stephen Miller and JD Vance, they’re going to go after constitutionally protected speech.'”

But he added: “No no no! We’re going to go after the NGO network that foments, facilitates and engages in violence” – a reference to non-governmental organizations. (AP)