Why will they say "we have no king"?
Rashi: When the evil comes, they will say, the king that we trusted in Him, that he will go out first and fight our wars, he did not help us at all.
Radak: When they go to Galus, they will say that it is as if we have no king, for he has no strength to save us from our enemies. When we requested a king, we thought that he will fight our wars.
Malbim: Via saying this, they will rebel against their king and want to depose him.
What is the significance of "Ki Lo Yareinu Es Hashem"?
Radak: Hashem was our King! We did not need [another] king. Hashem would have saved us from our enemies, when we do His will. Since we did not fear Him, and we abandoned His Torah - the king that we requested, what will he do? He cannot save us, since Hashem is angry at us, for we sinned. So Yisrael will confess in Galus.
Malbim: We do not fear Hashem; we do not consent to a king who wants to cease serving the calves, and establish Avodas Hashem in place of them.
Why does it say "veha'Melech Mah Ya'aseh Lanu"?
Malbim: How can the king force us to serve Hashem and fear Him?
