I think the Bible teaches this pretty clearly...
Mat 7:13,14 Enter by the narrow gate; for the gate is wide and the way is broad that leads to destruction and many are those who enter by it. For the gate is small and the way is narrow that leads to life, and few are those who find it.
Obviously the majority here is not right.
How about Rev 12:9? And the great dragon was thrown down, the serpent of old who is called the devil and Satan, who deceives the whole world.
Since he's said to be in the process of deceiving the whole world, then again, the majority must be deceived... and not right.
Jesus told his disciples on the night before His death, "If the world hates you, you know that it has hated Me before it hated you. If you were of the world, the world would love its own; but because you are not of the world, but I chose you out of the world, therefore the world hates you." (John 15: 18,19) World would refer to the majority, and the system of thinking held to by that majority...
Although our system of government is based to a degree on majority rule, it didn't really start out that way. The founding fathers limited to the voting franchise to men with property, and thus to people with a vested interest in taking that right seriously, especially as it relates to taxation. The Greeks demonstrated that when you go with a simple majority and let everyone vote, all you end up with is a bunch of irresponsible have-nots trying to take from the haves. It's human nature. We have sick heads and deceitful hearts (Isaiah 1:5,6 ; Jeremiah 17:9). We are filled with insanity and evil (Eccl 9:3)
If you add up the sick heads, the deceitful hearts, the fact that there are ways that seem right to us that end in death, that we don't even know our own motives half the time. That we are easily deceived and led about by our emotions and lusts, that there is a deceiver at work, with schemes and plans to lead us astray... how could you ever think the majority was right? How could you ever think that consensus is the way to go?
Because, I suppose, it's hard for human nature to go against consensus...