Trump or Pence swearing officials in? Has this been done in the past by the POTUS or VPOTUS?

Occasionally in the news I have heard that the President or Vice President has sworn in some new appointee. According to my Black’s Law Dictionary, the POTUS is the supreme magistrate of the land, so it seems there’s nothing illegal or unconstitutional about this. Still it seems odd. Have sitting Presidents or VPs ever done this in the past?

Or does the authority to swear in new appointees rest in their status as officers of the United States?

SFAIK there’s a constitutional or statutory (depending on the office) requirement that the office-holder should take the oath, but there’s no legal requirement that it should be administered by anybody, or taken in the presence of anybody. It makes sense that the oath should be taken in the presence of reputable witnesses, so that afterwards there should be no question about whether the oath was taken or not, but the whole business of the oath being administered by a judge (or anyone else) appears to be entirely ceremonial, and to have no legal significance.

I dare say that the oath being administered by a functionary as the POTUS or VPOTUS beams on encouragingly beside, would count in as them ‘swearing someone in’.

Swearing in high-ranking administration officials is a pretty common ceremonial duty of the vice president, and definitely happened before the current administration.

The Vice President has traditionally sworn in Senators, as part of his official role as president of the Senate.

The President swears people in because, well, he’s the President.

Note that when Neil Gorsuch joined the Supreme Court, he was sworn in by Chief Justice Roberts, and when Roberts became Chief Justice, he was sworn in by John Paul Stevens, who was the Court’s senior member.

I think that the swearing-in of junior officials by the P or the VP is being done in the capacity of being their ultimate supervisor; it’s akin to an executive order. AFAIK, the President cannot administer oaths more generally outside the executive branch. That’s a judicial function (which is why couples can go to the courthouse to get married, but not the White House).

The reference to the President as a “supreme magistrate” strikes me as some sort of obsolete locution, as no one now conceives of the President as a judicial officer.

Calvin Coolidge was sworn in as president by his father, whose only public office was that of a notary public. So anyone can give the oath of office, and at any level.

5 US 2903 (emphasis added) provides that:

So, presumably the Vice President’s authority comes from that statute.

This article suggests that it has been historically common for the Vice President administer oaths to cabinet secretaries.

I do not know where the President’s authority to administer the oath comes from, but the article above notes that past presidents have administered the oaths as well.