The Meaning of Tāghūt According to the Early Scholars & That It Does Not Necessitate Kufr in Every Case.
The word tāghūt  is mentioned in several places throughout the Qurān and its meaning is distorted by the radical preachers to refer to the disbelievers or to major idolatry, and since some of the great scholars mentioned in their writings that ‘the one who does not rule by that which Allāh has revealed’ is a tāghūt, then they conclude that all of the rulers are therefore disbelievers.
However, the reality is that the term tāghūt can refer to the unbelievers and to the heads of misguidance from the Muslims. I will prove this from the sayings of the great scholars of the past. Imām al-Jawharī stated in as-Sihāh:
“At-Tāghūt: the soothsayer, Satan and every leader of misguidance.” 
The esteemed scholar of the Arabic language, Ibn Mandhūr stated:
“At-Tāghūt: Whatever is worshipped besides Allāh, the Mighty and Majestic; and every leader of misguidance is a tāghūt.” 
He also stated:
“Abū Ishāq said: Everything that is worshipped besides Allāh, the Mighty and Majestic, is a sorcerer and a tāghūt. It is said, ‘[Everything that is worshipped besides Allāh:] the sorcerer, the tāghūt, the soothsayer and Satan…
Ash-Shaʿbī, ʿAtā’ and Mujāhid all said: ‘The sorcerer, the magician. At-Taghūt is: Satan, the soothsayer and every head of misguidance.” 
Imām Mālik (died 179H, rahimahullaah) explained:
“At-Tāghūt: Everything that is worshipped besides Allāh.” 
Ibn al-Jawzī said:
“As for at-Tāghūt: it is a term taken from tughyān, and it is to go beyond the set limits.” 
Regarding the statement of Allāh, “And We sent a Messenger to every nation calling them to the worship of Allāh and to abandon the at-Tāghūt”, al-Qurtubī, the famous Quranic commentator, stated: “Meaning: Abandon everything that is worshipped besides Allāh such as Satan, the soothsayers, the idols, and everyone that calls to misguidance.” 
And Imām ash-Shawkānī stated the same in his Quranic commentary, Fath al-Qadīr .
Ibn Hishām, the writer of the famous biography of the Prophet (salallaahu ‘alaihi wassallam), stated:
“At-Tāghūt: Everything that misguides from the truth.” 
Shaikh al-Islām Ibn Taymiyyah (d. 728, rahimahullaah) stated regarding at-Tāghūt:
“It is a generic title into which enters: the Satan, the idols, the soothsayers, the dirham, the dīnār (forms of currency) and other than that.” 
Shaikh Muhammad bin Sālih bin ʿUthaimīn (rahimahullaah) stated:
“Ibn al-Qayyim has gathered what has been said regarding it (at-Tāghūt), it is: ‘That which is exceeded by the servant beyond its limit whether it be with respect to following, or worship or obedience.’” 
The Meaning of Tāghūt According to Shaikh al-Islām Muhammad bin ʿAbdul-Wahhāb
It is somewhat surprising that modern-day radicals should attempt to utilise the statements of Shaikh Muhammad bin ʿAbdul-Wahhāb (rahimahullaah) to support their argument since he was from the scholars who consistently warned from the performance of takfīr and from disobeying the Muslim rulers, even if they be from the most tyrannical of rulers, as he has expressed in the famous letter to the people of al-Qasīm, ar-Risālah ilā Ahlil-Qasīm .
Regarding the discussion surrounding the subject of at-tāghūt, Shaikh Muhammad bin ʿAbdul-Wahhāb said:
“The tāghūts are many, and their heads are five:
- Iblīs (Satan), may Allāh’s curse be upon him,
- The one who is worshipped and he is pleased with that,
- The one who claims anything from the knowledge of the Unseen,
- The one who calls people to worship him,
- The one who judges by other than that which Allāh has revealed.
And the proof is His saying, the Most High:
“There is no compulsion in religion. Verily, the Right Path has become distinct from the wrong path. Whoever disbelieves in at-Tāghūt and believes in Allāh, then he has grasped the most trustworthy handhold that will never break. And Allāh is the All-Hearer, All-Knower.”
And this is the meaning of lā ilāha illallāh.” 
So some may understand from this that the Shaikh is declaring as an unbeliever the one who rules by other than what Allāh has revealed. However, this is not the case for two reasons: Firsty, due to the consensus from Ibn ʿAbdul-Barr who narrated that ruling by other than what Allāh has revealed constitutes minor disbelief that does not exit from the fold of Islām (At-Tamhīd of Ibn ʿAbdul-Barr, 5/74-75), and secondly that the term at-Tāghūt does not necessitate major disbelief. This is made very clear in the following statement of Shaikh Muhammad bin ʿAbdul-Wahhāb:
“The tāghūts are many, and the clear ones to us from them are five:
The first of them is Satan.
The tyrannical ruler.
The one who takes bribery.
The one who is worshipped and pleased with that.
The one who acts without knowledge.” 
So he considered that from the heads of the clear tāghūts are: the tyrannical ruler, the one who takes bribes and the one who does not act upon knowledge – and these affairs constitute minor disbelief (al-kufr al-asghar) in their origin. Indeed the one who takes bribes is not an unbeliever outside of the fold of Islām by the consensus (ijmāʿ) of the scholars, unless he makes that permissible. So this makes it perfectly clear that the Shaikh and the scholars before him did not restrict the title at-Tāghūt to only the disbeliever, rather the term can also refer to a Muslim upon sin or tyranny or the one who does not act upon knowledge or the person of misguidance who misguides others, such as the ideological heads of the Khārijites.
So from this we can conclude the term Tāghūt includes the disbelievers, the heads of misguidance and innovation – so it is not permissible after this clarification to ascribe to Shaikh al-Islām Muhammad bin ʿAbdul-Wahhāb that he declared as disbelievers the tyrannical rulers or those who do not rule by that which Allāh has revealed, using as a proof his speech regarding at-Tāghūt. And the same can by said of the other scholars as I have stated regarding Shaikh al-Islām Muhammad bin ʿAbdul-Wahhāb.
1 Singular: tāghūt; plural: tawāghīt.
2 See Mukhtār as-Sihāh, p. 265.
3 Lisān al-ʿArab 8/444.
4 Lisān al-ʿArab 15/9.
5 Reported by Ibn Abī Hātim with an authentic chain of narration, 2/495, 3/976.
6 Zād al-Masīr, 2/125.
7 Tafsīr al-Qurtubī 10/103.
9 As-Sīrah an-Nabawiyyah, 3/100.
10 Majmūʿ al-Fatāwā, 16/565-566.
11 Al-Qawl al-Mufīd, 1/10-12.
12 Recently printed with the title Sharh ʿAqīdah al-Imām al-Mujaddid Muhammad bin ʿAbdul-Wahhāb, explained by Shaikh Sālih al-Fawzān. Translated into English with the tile, The ʿAqeedah of Muhammad ibn ʿAbdul-Wahhaab; published by Sunnah Publishing, Michigan, USA.
13 Ad-Durar as-Sanniyyah, 1/136.
14 Ad-Durar as-Sanniyyah, 1/137.