Clearly there weren’t very many of the righteous among this crowd. When Amulek is able to turn the focus upon the sins of the lawyers, the people are even more angry. This crowd that was almost ready to believe with the second witness (verse 12) is now angrier than ever. What changed?
The people have to have accepted the lawyers as legitimate representatives of their way of believing. If we borrow the way this might have worked from the Maya example, the lawyers would be among the elite and would be seen to govern by some nearly divine right. Thus Amulek’s suggestion that they were on the side of the devil might appear almost as blasphemy to them.