Not Fathomable

It is simply not fathomable that a Constitution that grants Congress the power to remove a president for reasons including criminal behavior would deny Congress the power to investigate him for unlawful conduct -- past or present -- even without formally opening an impeachment inquiry.

Congress plainly views itself as having sweeping authority to investigate illegal conduct of a president, before and after taking office.  This court is not prepared to roll back the tide of history. ...

Thus, it is not the court's role to decipher whether Congress's true purpose in pursuing an investigation is to aid legislation or something more sinister such as exacting political retribution.

-- U.S. District Court Judge Amit Mehta ruling in Trump v. Committee on Oversight and Reform that President Trump cannot block the committee's subpoena to Trump's accountant, Mazars, Esquire, 21 May 2019