1)
They asked improperly. Why should Shmuel heed them?
1.
Malbim: Now they revealed their desire, they are not worthy of miraculous Hashgachah, which is only for Tzadikim of complete Emunah. Now they need a king to guide them according to nature.
2)
What must Shmuel testify to them?
1.
Rashi: He must warn them [about the laws of a king] so his fear will be on them.
2.
Malbim: Since they do not want a king to judge based on Torah law, rather, one who makes laws according to his whim, [the following] are the consequences.
3)
What is "Mishpat ha'Melech"?
1.
Radak citing Targum Yonasan: It is the laws pertaining to the king.
