Back in 1974 Congress subpoenaed various documents from President Nixon, including, most famously, the tapes of his Oval Office conversations. Nixon refused to hand them over, but the Supreme Court ruled unanimously that he had to comply. A couple of weeks later Nixon resigned.
For a while, that was that: the court had spoken, and presidents had to comply with congressional subpoenas for use in a criminal trial. A generalized interest in confidentiality was not enough to override a legitimate judicial need.
This was a landmark case, but the Trump administration says it’s hokum:
DEVELOPING Trump Justice Dept. asks U.S. judge to reject House Judiciary Committee request for Mueller grand jury materials, argues courts in 1974 wrongly gave Congress the Watergate grand jury ‘roadmap’ that led to President Nixon’s impeachment.
— Spencer Hsu (@hsu_spencer) October 8, 2019
“Wow, O.K.,” responded U.S. Chief District Judge Beryl A. Howell of Washington, D.C., sounding unpersuaded. “As I said, the department is taking an extraordinary position in this case.”
— Spencer Hsu (@hsu_spencer) October 8, 2019
Apparently the Trump argument is that the grand jury materials would be really helpful to the Democrats pressing for impeachment, so they should be held back. Judge Howell seems unpersuaded, but I’m sure the Trumpies don’t care. She’s just an Obama flunky anyway and obviously prejudiced against them. They’ll just appeal, and then appeal again. The point here is mainly to take up lots of time, not to actually win the case.