He says: What is the ruling on someone who says that the rulers do not have a legitimate pledge of allegiance because they do not rule by what Allah has revealed?
Okay, what if someone says: the rulers do not have a legitimate pledge of allegiance because they drink alcohol.
The rulers do not have a legitimate pledge of allegiance because they deal with usurious banks and permit them. The rulers do not have a legitimate pledge of allegiance because they are undutiful to their parents. It never ends.
The issue is: is he a disbeliever or a Muslim? That is the ruling.
If he is a disbeliever, then he does not have a legitimate pledge of allegiance.
Because Allah, the Blessed and Exalted, says: O you who have believed, obey Allah and obey the Messenger and those in authority among you, meaning believers.
Among you from the believers, and Allah the Blessed and Exalted says: Allah will never give the disbelievers a way over the believers.
There is no way greater than ruling, so it is not allowed.
Declaring the rulers disbelievers because they do not rule by what Allah has revealed, and this is indeed a very great sin, but the issue of declaring disbelief.
With this, and we say he does not have a legitimate pledge. We say if you judge him to be a disbeliever, then yes, he does not have a legitimate pledge.
But the correct view is that we have detailed this, there is detail in this matter, the issue of ruling by other than what Allah has revealed.