We don’t cover every Trump-Russia story here at FiveThirtyEight. Some of them can be repetitive, such as the many iterations of the now-familiar narrative around the controversial work that President Trump’s onetime campaign chairman, Paul Manafort, did in Ukraine. Others are heavily reliant on unnamed sources or make vague claims, which means they’re complicated to understand and hard to verify.

But The New York Times’s weekend story, which details Donald Trump Jr.’s meeting last June with a Russian lawyer from whom he hoped to receive negative information about Hillary Clinton, is significant. It has the potential to stick to the president for three reasons:

First, this meeting involved President Trump’s inner circle. Manafort and Jared Kushner joined Donald Trump Jr. at the meeting, which is important because they were two of the top officials in Trump’s presidential campaign at the time.

But this meeting also involved one of president’s sons. The president will have trouble distancing himself from Donald Trump Jr. the way he did from Manafort, Michael Flynn, Carter Page and others in his orbit who have publicly confirmed dealings with Russian figures. Even if the president did not attend and was not informed about this meeting, as a spokesman for his attorney told the Times, it’s hard to imagine any campaign personnel who would be more closely connected to him than one of his children.

Secondly, Trump Jr.’s reason for being at the meeting is at the core of the Russia controversy: He was hoping to undermine Clinton. President Trump has vehemently denied that he encouraged or was behind the hacking of the Democratic National Committee or the email of top Hillary Clinton adviser John Podesta. (During the campaign, however, Trump did publicly call on Russia to find and publish a set of 33,000 emails that had been deleted from Clinton’s private email server.)

But Trump Jr. acknowledged, in his statement to the Times, that his meeting with the Russian lawyer, Natalia Veselnitskaya, was pitched to him as a way to get negative information about Clinton. In fact, in his statement, he complained that Veselnitskaya, instead of providing information about Clinton, turned the meeting into a discussion about a U.S. law called the Magnitsky Act, which allows the U.S. to freeze the assets of Russian officials accused of human rights violations.

“Claims of potentially helpful information were a pretext for the meeting,” Trump Jr. said in his statement, confirming that he attend the meeting in hopes of getting negative information about Clinton from the Russian lawyer and that he viewed such information as “helpful.”

Other officials close to the president who had meetings with Russian officials, including Kushner and Attorney General Jeff Sessions, have never confirmed that those meetings were about the 2016 election or weakening Trump’s election opponent. Regardless of whether Trump Jr.’s June meeting rises to the level of “collusion,” this is the first direct acknowledgement that close associates of Trump privately welcomed Russian help in the 2016 election.

Third, the story is well-sourced and includes support from on-the-record sources. Many of the stories about Trump and Russia are full of unnamed sources making complicated accusations. Not this one. Trump Jr. admits on the record that he attended the June 9, 2016, meeting. Other sources in the piece are anonymous but include people close to the White House.

Because the sources are close to the president, it’s possible that the story could be the tip of the iceberg, eventually leading to evidence of deeper collusion between the Trump campaign and Russia. But none of that has been proven yet. It’s not clear whether it’s illegal for the Trump campaign to seek out or accept negative information about a political rival from the Russians. The meeting in no way proves that the Trump campaign or the president himself asked or encouraged Russian officials to hack into the DNC or Podesta’s email systems. And Trump Jr., in his statement, says the lawyer did not provide him with useful information about Clinton.

But whatever the legal implications of this story, it is almost certainly a major political problem for Trump. This is the latest and perhaps most explicit revelation about a series of interactions between Trump allies and Russia, which took place during a period in which Russia prepared and executed a hack that both parties say is deeply concerning to them. And the revelation came in the same weekend that Trump tried to downplay the likelihood of Russian meddling in the campaign following his meeting with Vladimir Putin. News of last summer’s meeting may be the biggest Russia-related development since the president fired FBI Director James Comey and subsequently suggested that the firing was motivated in part by Comey’s refusal to end the bureau’s Russia investigation.