There is no "technical."
"The President shall be Commander in Chief of the Army and Navy of the United States, and of the Militia of the several States, when called into the actual Service of the United States; he may require the Opinion, in writing, of the principal Officer in each of the executive Departments, upon any Subject relating to the Duties of their respective Offices, and he shall have Power to grant Reprieves and Pardons for Offenses against the United States, except in Cases of Impeachment."
That's it. That's the whole thing. That's all it says. There's no technicality beyond that.
Everything else is either tradition or someone's interpretation.
ON the other hand, back in the 1970s (when Nixon was all the rage) the Department of Justice stated the following:
"Under the fundamental rule that no one may be a judge in his own case, the President cannot pardon himself".
I think their argument is that even though the section on pardons doesn't say anything about self-pardons, a pardon has the president acting as a judge of sorts.
Some legal opinions. From:
CNBC
Against pardoning himself:
"The better view is that a ban on self-pardons is implicit. Giving the president the power to be a judge in his own criminal case is inconsistent with this being a rule of law society"
"... much of constitutional law is based on reasoning from the underlying design of the Constitution and the structures it creates, and a presidential self-pardon is so radically inconsistent with the Constitution’s commitments to (1) limited government; (2) the separation of powers; (3) and elected officials being accountable to the rule of law"
"In US v. Nixon, the Court basically said that Nixon as the subject of a criminal investigation did not speak for the government and therefore could not withhold the tapes from the prosecutor who did. This case teaches that the president cannot act in an official capacity to benefit himself against an authorized criminal prosecution."
"A pardon is by its very nature when one person pardons another. The point is, the constitution uses the word pardon, and a pardon is by very nature a situation that involves two people"
In favor of pardoning himself:
"There is no expressed limitation governing whom the president may or may not pardon. Therefore it seems quite clear to me that the President may pardon himself"
