How do we refute the one who says that criticism of Dā`ish is like criticism of the ruler because they have conquered the lands they rule and they have the support of those with power and influence?

Shaykh Sulaymān ibn Abdīllah Abul-Khayl:

The answer to that is that this comment is wrong and there is no truth to it. This is because the places and countries they revolted against are under the authority of rulers and systems that were already in place prior to their revolt. All the scholars and people with intelligence, and actually, all Muslims and non-Muslims agree with this fact. Proof enough is the fact that the Ummah of Muḥammad will never unite over an aspect of misguidance, while they are united over the fact that these people are dissenters, renegades, and traitors who follow the way of the Khawārij whom Allāḥ described as He has described.

Moreover, we have explained earlier the descriptions His Messenger gave to them using the traditions we presented as proof. Therefore, the one who made this comment should fear Allāḥ and put an end to this misguidance and these false claims of his, and follow what is in the Book of Allāḥ and the Sunnah of His Messenger, as well as the way of Ahl us Sunnah wal Jamā`ah and the Pious Predecessors.