The conservative National Review launched a broadside against Republican presidential front-runner Donald Trump on Thursday, publishing a scathing editorial that called the billionaire "a menace to conservatism."
The magazine also published accompanying essays by 22 conservative thinkers opposing Trump's candidacy. Its cover carries the name of the National Review and the words "Against Trump."
"Trump is a philosophically unmoored political opportunist who would trash the broad conservative ideological consensus within the GOP in favor of a free-floating populism with strong-man overtones," the editors say in the beginning of the piece.
Trump immediately dismissed the attack on Twitter, calling the magazine a "failing publication" that had lost its way. The Republican National Committee disinvited the magazine from a Feb. 25 GOP debate in Houston in response.
The magazine blasted Trump as clueless on foreign policy — inconsistent on how he would fight the terror group ISIS and too accepting of praise from Russian President Vladimir Putin.
"He is fixated on stealing Iraq's oil and casually suggested a few weeks ago a war crime — killing terrorists' families — as a tactic in the war on terror," the editors wrote.
It called Trump's plan to deport 11 million undocumented immigrants as beyond the capacity of the government.
"Donald Trump is a menace to American conservatism who would take the work of generations and trample it underfoot in behalf of a populism as heedless and crude as the Donald himself," the editorial says in its closing sentence.
Trump hit back on Twitter, and later in comments to reporters before an event in Las Vegas.
"The National Review is a dying paper; its circulation is way down," Trump told reporters. "Not very many people read it anymore … I guess they wanted to get a little bit of publicity, but that's a dying paper."
The National Review was started by William F. Buckley in 1955. Trump last week referenced the magazine's founder in rebutting criticism by rival Ted Cruz about "New York values." Buckley was born in New York City.
The National Review says its 2015 audited circulation is 150,000, and that it is the largest-circulation conservative magazine in the nation.
National Review publisher Jack Fowler wrote late Thursday that after the "Against Trump" editorial was published, a top RNC official called to disinvite the magazine from the February debate.
RNC chief strategist and communications director Sean Spicer confirmed that the magazine was disinvited.
"We expected this was coming. Small price to pay for speaking the truth about The Donald," Fowler wrote in a blog post Thursday.
This story originally appeared on NBCNews.com