You get the legal advice you might not pay for

Trump’s decision to ask for a special master to review his extensive trove of top secret materials was almost certainly a massive blunder:

Former President Donald J. Trump may have thought that he was playing offense when he asked a federal judge last week for an independent review of documents seized from his residence in Florida — a move that, at best, could delay but not derail an investigation into his handling of the records.

But on Tuesday night, the Justice Department used a routine court filing in the matter to initiate a blistering counteroffensive that disclosed new evidence that Mr. Trump and his legal team may have interfered with the inquiry.

In the filing, in Federal District Court for the Southern District of Florida, department officials revealed more details about the classified materials that Mr. Trump had taken from the White House, including a remarkable photograph of several of them arrayed on the floor of Mar-a-Lago, his home and private club in Florida. In what read at times like a road map for a potential prosecution down the road, the filing also laid out evidence that Mr. Trump and his lawyers may have obstructed justice.

It was as if Mr. Trump, seeming not to fully grasp the potential hazards of his modest legal move, cracked open a door, allowing the Justice Department to push past him and seize the initiative.

Sometimes he seems to forget that he’s not just trying to litigate Atlantic City contractors into surrender anymore.