Michael Wolff’s book offers ‘damning’ evidence against Trump in obstruction case: conservative columnist
President Donald Trump takes a moment before taking the stage during a Memorial Day ceremony at Arlington National Cemetery in Arlington, Va., May 29, 2017. (DOD photo by U.S. Air Force Tech. Sgt. Brigitte N. Brantley)

Michael Wolff's explosive new book presents a new set of problems for President Donald Trump and his aides in the special counsel investigation.

Two claims in particular will likely interest special counsel Robert Mueller as he investigates potential Trump campaign ties to Russia -- and efforts to cover up or obstruct possible criminal activity, according to Washington Post columnist Jennifer Rubin.

Wolff describes in new detail how the president personally dictated a statement July 8 aboard Air Force One on Donald Trump Jr.'s meeting with a Russian attorney, in response to a forthcoming report by the New York Times.

The story offered by Trump Jr. -- with his father's reported guidance -- fell apart over the next three days, and the president's son eventually released emails showing he had been promised damaging information about Hillary Clinton as part of Russian government efforts to assist the Republican presidential campaign.

"This is damning both because it involves an effort arguably to cover up the real purpose of the meeting," wrote Rubin, a conservative, "and, more important, because Trump was personally involved."

Rubin said the claims presented in Wolff's book, if accurate, would be a "powerful element" in a potential impeachment case on obstruction of justice.

According to Wolff's book, the spokesman for Trump's personal legal team quit because he believed the president had committed a crime that day.

"Mark Corallo … believed the meeting on Air Force One represented a likely obstruction of justice (and) quit," Wolff wrote, according to Axios.

Mueller won't necessarily be interested in Corallo's opinion, Rubin said, but he will likely interview the former spokesman about what evidence he witnessed to help him form that conclusion -- if he hasn't already spoken to the special counsel team.

Wolff also reported another key detail likely to catch Mueller's eye, Rubin wrote.

Former chief strategist Steve Bannon told Wolff that he believed Trump Jr. had invited Russian officials he met with, along with brother-in-law Jared Kushner and then-campaign manager Paul Manafort, up to his father's office at Trump Tower.

Trump has denied meeting with them, but Rubin said Mueller would likely question Bannon about his claims and interview other potential witnesses who would have been present that day in June 2016.

Eventually, Mueller may even question the president himself, Rubin pointed out.

Mueller may also study Wolff's book to determine whether anyone told the special counsel's investigators something different from what they said to the author.

"Federal prosecutors like Mueller and his team don’t interview people without FBI agents present, and lying to the FBI is a crime, as Flynn and Papadopoulos know well," said former federal prosecutor Renato Mariotti.