http://www.osteocushion.com/trickery/metodon-v-lodeynom-pole.html Barring Krishna, Vidura was most respected as an adviser by the Pandavas, whom he forewarned on various occasions of Duryodhana’s plots to exterminate them, such as Duryodhana’s plan to burn them alive in the house of wax. Excepting the prince Vikarna, Vidura was the only one who protested against the humiliation of Draupadi in the Kaurava court. In that moment, Duryodhana viciously rebuked Vidura, calling him ungrateful. Dhritarashtra moved to rebuke Duryodhana for insulting Duryodhana’s uncle, but, remembering Vidura saying that a blind man cannot be king, holds his tongue, and instead reprimanded Duryodhana for insulting the prime minister. It is that incident that Vidura brought up years later when he severed ties with the Kurus and sided with the Pandavas at the onset of the Kurukshetra war. Unlike Bhishma, Dronacharya, Kripacharya, Karna, etc., Vidura did not have an obligation to Hastinapur or Duryodhana, but to his family. Hearing Dhritarashtra not acknowledge that relationship, Vidura felt compelled to side with dharma and the Pandavas.