The blind leading the blind
Matthew 15:14 reads: 'Leave them alone; they are blind leaders of the blind. When the blind lead the blind, all shall fall into the ditch.'
This was part of Jesus' strong criticism of the religious leaders of his day. He felt they did not know what they were doing and led equally immature people. This could only end in disaster, he warned.
Here are two examples of the blind leading the blind: a useless coach and captain leading a poor team, and a group of misguided politicians leading ignorant people. Sadly, they are unlikely to succeed.
There is a related, very old saying: 'In the kingdom of the blind, the one-eyed man is king.' This can be used to explain the success of some people who do not seem to be very talented. If one person knows just a little bit more than the others, he may become their leader.
However, blind people are no longer considered a liability. H. G. Wells sensed this when he wrote the story The Country of the Blind. It is about a society of blind people who live in a hidden valley and function very well. The people have acute hearing and can meet all their needs.