The Torah in Parashat Shoftim (Debarim 17:15) commands appointing a king, and then warns, “Lo Tuchal La’tet Alecha Ish Nochri Asher Lo Ahicha Hu” – “You cannot place over yourself a foreigner, who is not your brother.” This verse introduces a Biblical prohibition against naming a non-Jew to the kingship.
More generally, the Sefer Ha’hinuch writes, the Torah here teaches us that we must appoint to important positions of leadership only qualified individuals. We must not appoint unqualified or evil individuals to leadership positions out of nepotism, fear, or to flatter rich or powerful people. The Sefer Ha’hinuch warns that if somebody does appoint an evil person to a position of leadership, “Lo Tasur Ra’a Mi’beto” – “evil will never leave his household”; meaning, he will be severely punished. Conversely, those who fearlessly do the right thing, and appoint qualified leaders, motivated purely by genuine concern for the public’s benefit, will be rewarded.
This Misva is binding when Beneh Yisrael reside in their land and appoint a king. It is directed not toward any particular individual or group of individuals, but toward the entire nation collectively.
The Mishna in Masechet Sota (41a) tells that Agripas, one of the kings of Judea during the time of the Second Temple, read this verse, which forbids appointing a foreigner as king, and began weeping. He was a descendant of Hordus (Herod), a non-Jew who worked as a servant for the royal Hashmonai family, and later killed all the Hashmonaim and seized the throne. Agripas, his descendant, realized upon reading this verse that he was not worthy of the throne, and so he began crying. The people assured him, “Al Tira, Ahinu Ata” – “Do not be afraid; you are our brother.” The Gemara comments that the people committed the grave sin of false flattery by wrongly comforting Agripas, assuring him that he was eligible to be king, when, in fact, he was not. They responded this way in order to ingratiate themselves to the king, a grievous misdeed for which they were punished.
The Rishonim debate the question as to the precise nature of Agripas’ disqualification. Rashi maintains that Agripas’ mother was Jewish, and thus he was, in fact, eligible to serve as king. However, since his father descended from Hordus, a servant, Agripas’ appointment as king denigrated the kingship. According to Rashi, it seems, Torah law permitted Agripas to serve as king, and he was disqualified only Mi’de’rabbanan (by force of Rabbinic enactment), out of concern for the dignity and respect of the monarchy. Tosafot disagree with Rashi’s understanding, contending that the people would not be deserving of severe punishment for approving of Agripas’ appointment if it were allowed on the level of Torah law. Therefore, Tosafot advance a different view – that only somebody with both a Jewish mother and a Jewish father may be appointed king. Hence, Agripas was disqualified from the kingship on the level of Torah law, and the people were thus guilty of false flattery by falsely assuring him that he was eligible for the Jewish monarchy. (Yet a third view is advanced by Tosafot in Masechet Yebamot (45), stating that neither of Agripas’ parents were Jewish.)
Even though we do not have a monarchy nowadays, nevertheless, as mentioned, this Misva is relevant in our time, requiring us to appoint to leadership positions only people who are truly qualified, and not to appoint leaders out of nepotism or in the interest of pleasing wealthy, powerful individuals.