Donald Trump denied political reporters press credentials to attend one of his campaign events in direct retaliation for a Tuesday editorial published by the Des Moines Register that called for the real estate mogul to drop out of the Republican nomination race. Trump’s campaign manager told a Register columnist that the decision to deny the paper credentials was in reaction to the editorial. The Register later said that it works hard to maintain a distance between editorials, which are opinion pieces, and news reporting.

Keeping reporters out of a campaign event is a fairly uncommon step for a presidential candidate. Iowa is the first caucus in the nation, and a win or loss in the state for a normal candidate -- which Trump clearly is not -- can have dramatic effects on a candidate’s fundraising and polling prospects. That may not matter to him, given a surge in the polls that has thrust him into first place nationally and his considerable personal wealth, which he claims to be in excess of $9 billion.

"As one of the most liberal newspapers in the United States, the poll results were just too much for them to bear," Trump said after the editorial was published.

The Register editorial asked that he discontinue his candidacy and detailed ways in which the paper said Trump did not belong in a presidential race. Candidates are people who must devote themselves to public service and endure significant financial and personal sacrifices in order to inhabit the highest office in the country. “That is problematic, because Trump, by every indication, seems wholly unqualified to sit in the White House. If he had not already disqualified himself through his attempts to demonize immigrants as rapists and drug dealers, he certainly did so by questioning the war record of John McCain, the Republican senator from Arizona,” the editorial reads .

The editorial later calls him a “distraction with traction” and a “feckless blowhard” who has risen in the polls without provoking real thought about important issues.

It is not the first public battle with a news organization. Last week, Trump released a statement that called the Huffington Post “unimportant” and a “glorified blog.” The Huffington Post has relegated coverage of Trump from the political section to the website’s entertainment section. Trump also told CNN’s Anderson Cooper in an interview that the American people “don’t trust you and the media.”

In an average of polls by Real Clear Politics, Trump is the clear front-runner nationally, beating out his closest rival, former Florida Gov. Jeb Bush, by nearly 5 percentage points.