From the story here:
In court filings last week the Department of Justice deployed what could be the nuclear option in its latest effort to prevent President Trump from declassifying information regarding FISA warrants used to spy on his campaign aide Carter Page: It is claiming that such a move would interfere with Special Counsel Robert Mueller’s investigation.
This is the first time the DOJ has explicitly made this argument implying personal peril for the president, since interference could open Trump to charges of obstruction of justice. Until now, the department has argued that declassifying the documents threatened national security.
In the 178-page court document, DOJ officials said they had “determined that disclosure of redacted information in the Carter Page FISA documents could reasonably be expected to interfere with the pending investigation into Russian election interference."
That rationale has heightened suspicions among congressional investigators that the special counsel is being used to prevent the disclosure of possible FBI abuses and crimes committed during the Russia probe. ...
[S]ources told [Real Clear Investigations] that the president and the DOJ are at a standoff. “Trump knows that what’s in those documents clears him of all the collusion stuff,” said a third congressional source, “and it shows the FBI was doing some very bad things.”
But what’s now keeping Trump from pulling the curtain back on the Russia investigation is the probe itself. “That’s the leverage the DOJ has on Trump,” explained this source. “Nothing on Russia or collusion or anything like that — it’s the actual investigation. If he’s seen to be interfering, they move to obstruction.”