Radak: Initially, when Yehudah had evil kings and people sinned, Hashem punished little by little, so he would not destroy Yerushalayim. Chizkiyah was good ? "v'Ganosi Al ha'Ir ha'Zos Lehoshi'ah Lema'ani" (Yeshayah 37:35). Afterwards, Menasheh was more evil than all before him, and Hashem bore him, and did not want to destroy Yerushalayim. Amon increased sin, and Hashem bore him. Yehoachaz and Yehoyachin are not counted, for each ruled only three months ¹ . Yehoyakim ² was the third. Tzidkiyah did evil ³ ? "Lo Ashivenu." Hashem did not want to pardon more; the Bayis was destroyed in his days.

Malbim: Idolatry, Arayos and murder. "Ma'asam Es Toras Hashem" is the fourth.

Radak: It is not the fourth. Rather, in the fourth [evil king]. Hashem punished for what they and their fathers did ? they despised Toras Hashem.

Radak citing Rav Sadya Gaon: Toras Hashem are Mitzvos above [human intellect; Chukav are Mitzvos that Sechel understands. (It is one matter ? all the Mitzvos.)

Malbim: They are one - because they despised His Torah, they did not guard His Chukim. It was not due to the Yetzer ha'Ra and desire, rather, due to denial and despising His Torah.

Radak: The Torah was written in the Beis ha'Mikdash [in Yehudah's portion], and they disgraced it and did not turn to it, to the point that they forgot it. It was a Chidush when the found the Torah in the days of Chilkiyah ha'Kohen!

Radak: The words of the false Nevi'im made them stray.

Malbim: False mindsets of Emunah caused their denial and despising Torah. Even though they are false, they persisted in them because their fathers followed them. They were like an inheritance from fathers to sons. Therefore, they will be punished.