Upvote:6
There is a bit of confusion here over the meaning of the word "magistrate".
Although "magistrate" is often the title of a judicial official in English-speaking countries, it once meant an executive official.
The English word "magistrate" ultimately derives from Latin magistratus.
Magistratus, derived from magister, was an overarching term to refer to the elected administrative offices in the ancient Roman republic: aediles, consuls, praetors, quaestors, tribunes, etc.
From A Dictionary of Greek and Roman Antiquities, (1890) William Smith, LLD.
Magistratus is properly the abstract form of the concrete magister, but it comes to be used indifferently to indicate the office and the person who holds it.
Following that, there is as concise a description of the powers of an executive as you can get in ancient Rome:
The powers of the municipal magistrates are discussed elsewhere [see COLONIA]; the following remarks apply to the magistrates of the populus and of the plebs. Every such magistrate has coercitio, the power within his proper sphere of duty to compel the citizens by force of punishment to obey him, and to avenge any act which argues contempt of his magisterial authority (in ordinem cogere magistratum). He has likewise the power of addressing the people by word of mouth (jus contionis) and by written proclamation (jus edicendi).
The founders of the American republic, who were often classically educated, took inspiration from the ancient Roman republic.
So when they referred to the President as "Chief Magistrate" they actually meant "Chief Executive", a term you may be more familiar with.
Such a reference may have been a form of prestige signaling, i.e. using a fancier word to show off (to those in the know) how well-educated you were.