What is the meaning of "Al Ken Tafug Torah"?
Rashi: Since Yisrael see [Nebuchadnetzar's] success, this blunts and removes Torah from them. They will heed him, and bow to the image in the valley of Dura.
Radak: Since You do not do judgment against Resha'im, this slackens and weakens Torah. Many slacken, for they see success of Resha'im and difficulties of Tzadikim. Tafug is slackening and weakening. The same applies to every word from this root.
Malbim: People claim that You blunt Torah. Via this Torah ceases ? it teaches the fundamentals of Emunah, that Hashem supervises and judges righteously. People deny this, for they see the Rasha succeed and the Tzadik dies.
What Mishpat is never carried out?
Rashi: He should be killed.
Radak: Mishpat against Resha'im.
Malbim: Mishpat of etiquette Bein Adam l'Chavero. Even though intellect obligates it (it is fixed in man's heart via nature, and will not depart), it is not carried out.
What is "Machtir"?
Rashi: He surrounds him [Radak - to do evil to him]. This is like "Abirei Vashan Kiteruni" (Tehilim 22:13).
Malbim: Even if the Tzadik wants to do Mishpat, he cannot, for the Rasha dresses the Tzadik with a crown. The Tzadik who judges is fixed to judge via the evil king. The Tzadik must conduct according to the Rasha's evil laws, which are crooked judgments.
Is the Mishpat crooked?
Radak: I say that it is crooked. Targum Yonasan is like this.
Malbim: Even Mishpat that is inwardly straight, externally it must be crooked, to appease the Rasha who puts the crown on his head; the Rasha does not want straight judgments.