The latest notch in the Donald Trump's total obstruction belt comes in the form of a letter from outgoing White House lawyer Emmet Flood urging Attorney General William Barr to block further inquiries related to the special counsel's report. Specifically in the April 19 letter, Flood asserts that Donald Trump has the power to assert executive privilege over both underlying evidence in the report and witnesses who gave testimony to Robert Mueller. Flood dubiously argues that just because Trump allowed his staff members to cooperate with the inquiry, he didn't waive executive privilege for basically anything, not the "underlying investigative materials" and not the right to "instruct his advisors to decline to appear" before Congress. In other words, Trump reserves the right to claim executive privilege on virtually anything and everything related to the report.
In the course of making his legal argument, Flood goes out of his way to skewer Mueller's prosecutorial judgment and his final work product, calling it "inexplicable" that Mueller's legal observations weren't more conclusive on one hand and yet faulting him for making "conclusive determinations" not to exonerate Trump of criminality on the other.
Mueller, Flood wrote, "produced a prosecutorial curiosity—part "truth commission" report and part law school exam paper" that was unfair to Trump. "Far more detailed than the text of any known criminal indictment or declination memorandum,” he said, “the Report is laden with factual information that has never been subjected to adversarial testing or independent analysis."
So effectively, Trump bent over backward to cooperate but he didn't waive any right whatsoever to executive privilege, and he got screwed by Mueller, who really just put too much research and investigative work into his inconclusive analysis.
Legal analysts like Lawfareblog's Benjamin Wittes were skeptical that Flood's arguments about privilege would prevail at the end of the day, especially given the fact that Barr himself said in testimony that he hadn't made executive privilege redactions to the report because Trump had waived the right. That assertion along with the reams of now-disclosed witness testimony really kills Flood's argument. Wittes told MSNBC that instead of being a sound legal strategy, it was more likely a "delaying tactic" aimed at "running out the clock" on Democrats' efforts to obtain further information and compel certain witnesses to testify.
To his point, the letter sure gives Barr cover to ignore the Judiciary Committee's subpoena for the full unredacted Mueller report.
In the meantime, the single-most important witness at the moment is Bob Mueller. Barr has said he has no objection to Mueller testifying, but the Justice Department hasn't been particularly cooperative in nailing down a date. But if push comes to shove and Democrats have to subpoena Mueller, he can opt to comply no matter what Trump or Barr tell him to do. One would think Mueller would be more interested than ever now, given Barr's testimony and Flood's letter, to set the record straight on an investigation that consumed him for two years and might ultimately set the stage for impeachment proceedings.