History
The Implications of Executive Privilege in Congressional Investigations
Quick fact
In the 1974 case United States v. Nixon, the Supreme Court unanimously rejected President Nixon's claim of absolute executive privilege, forcing him to release the Watergate tapes—showing the privilege is not unlimited.
Why this is interesting
You've heard presidents claim 'executive privilege'—but is that a real legal tool or just a way to avoid accountability? How far can a president go to keep secrets from Congress?