McGahn is seen as having unique and critical information into possible obstruction by Trump during the Mueller investigation.
"He is what all of this could switch on.
The subpoena says McGahn is "commanded" to attend.
Trump is taking Good Friday off, but woke up in Mar-a-Lago and took to Twitter to continue his attacks.
In reality it's a public relations ploy designed to give so-called “undecided” Republicans in the Senate cover to vote for Kavanaugh.
President Trump may have undone his own limitations on the FBI investigation of Brett Kavanaugh.
McGahn Testified Before Mueller for 30 Hours
Within the White House several top officials believe that Trump made a huge mistake in the early days of Mueller's investigation into Russian meddling in the...