There is no unrestricted partisanship to anyone besides the Messenger of Allaah
Al-Allaamah Zayd Bin Haadi Al-Madkhali (rahimahullaah) stated:
There is no (unrestricted) partisanship except to the Messenger of Allaah (sallal-laahu-alayhi-wasallam) because he is infallible and never speaks out of his desires. As for unrestricted partisanship to personalities whether they are correct or mistaken, then indeed this is not permissible for the seeker of knowledge. On the other hand, he should look to such and such Shaikhs as to which of them is upon uprightness and is following the Manhaj of the Salaf. This is the one whom we place our hands on his hands- not out of blameworthy blind following, rather due to the fact that he is upon the truth. So we agree with him upon truth and follow a singular path in obedience to the statement of Allaah (The Mighty and Majestic):
[وَأَنَّ هَٰذَا صِرَاطِي مُسْتَقِيمًا فَاتَّبِعُوهُ ۖ وَلَا تَتَّبِعُوا السُّبُلَ فَتَفَرَّقَ بِكُمْ عَن سَبِيلِهِ ]
“And verily, this is my Straight Path, so follow it, and follow not (other) paths, for they will separate you away from His Path. 6:153
As for the one who selects Shaikhs, leaders and guides, whilst being in agreement with them- in what is correct and wrong- to the extent that they do not leave their Manhaj whether they are correct or wrong, then these are the people who bring evil upon themselves and upon others. And if they do not repent, then they are most worthy of being blamed. So the affair-and all praise belongs to Allaah- is clear and it is not permissible for a person to be in confusion regarding this affair.
Therefore, we are with those who follow the straight path-we follow a singular path which Allaah (The Mighty and Majestic) has commanded us to follow and which the messenger called us to. And those you follow the wrong path or are mistaken in many of their affairs, or in some of their affairs, we leave him (i.e. we leave his mistakes or abandon him when he deserves to be boycotted). None is followed in everything except the Messenger of Allaah (sallal-laahu-alayhi-wasallam). As for the people, then indeed they can be correct or mistaken. Indeed, we do not follow them and we do not follow their footsteps solely because they are Shaikhs, Callers to Islaam, leaders or guides; rather you should be with the people of the Salafi Manhaj-those who follow the correct manhaj and correct understanding.
[العقد المنضد الجديد في الإجابة على مسائل في الفقه والمناهج والتوحيد -(page:144) ]