His testimony is likely to be overshadowed by the president’s news conference, but Attorney General John Ashcroft served notice yesterday that he is one administration player not afraid at all to go on offense against the Democratic louts on the so-called 9/11 commission. The full effect of the bombshell he dropped yesterday afternoon will take some time to settle.

“The single greatest structural cause for September 11 was the wall that segregated criminal investigators and intelligence agents,” he said in his stirring and air-clearing opening remarks. “Government erected this wall. Government buttressed this wall. And before September 11, government was blinded by this wall.”

Who built and reinforced this wall? Ashcroft pointed to Justice Department guidelines from 1995 that “imposed draconian barriers to communications between law enforcement and intelligence communities.” It was a system “destined to fail.” He pointed to investigations impeded by these rules, including efforts that might have nabbed three of the 9/11 conspirators weeks if not days before the attacks.

Then he got to his real point. The commission itself may not have known of the 1995 memorandum that laid out these guidelines — “so I have declassified it for you and the public to review,” Ashcroft told the commission. Next, the dagger: “Full disclosure compels me to inform you that its author is a member of this Commission.”

Ashcroft did not need to name names for all to know that he had just outed Jamie Gorelick, the long-time number two in the Clinton Justice Department and one of the most transparently partisan Democrats on the 9/11 commission.

Not only did Ashcroft add to the growing pressure on Gorelick to testify before the commission rather than serve on it, specifically about what she and the administration she served failed to do about terrorism. Above all, he discredited her in the eyes of her fellow commissioners. Clearly she had never informed them of this memorandum. Now they were caught by surprise and made to look foolish.

One could detect the power of Ashcroft’s bombshell in the subsequent questioning. Richard Ben-Veniste’s edge turned to smarm. He greeted the two surprise guests who had accompanied Ashcroft to the hearing, his respected former deputy Larry Thompson and Solicitor General Ted Olson. Ben-Veniste referred to him as “Mr. Olson,” and offered renewed condolences on the death of Barbara Olson on 9/11. With Olson on Ashcroft’s side, there was no way he could look bad.

Ben-Veniste’s only pointed question proved an embarrassment, repeating as it did morning press stories fed by Democrat leaks to the effect that Ashcroft would be asked about why he had started flying in government planes and not commercially before 9/11. When Ashcroft replied that all his personal flying had continued to be done commercially, as was his wife’s, Ben-Veniste was left red-faced, grasping at a dwindling number of straws.

But he couldn’t have been more red-faced than Gorelick. Initially she tried mouthing denials to fellow commissioners that she was author of the memo. But when a copy was handed to her, listing her as initialed author, she had nowhere to hide.

Her round of questions came last. Unlike Bob Kerrey, say, who was cordial with Ashcroft and even said it was good to see the AG “on the mend” after his recent hospitalization and operation, Gorelick established no human contact during her half-hearted queries — none of which engaged the central point of Ashcroft’s opening statement. The Democrats wanted to play hardball, but ended up clubbed on the head themselves.