What is the main argument of those who oppose the Butler Act?

The main argument of those who oppose the Butler Act is Examination of the prosecutor to demonstrate that belief in the historicity of the Bible.

Explanation:

This argument is from Scopes Trial also known as Scopes Monkey Trial. It was a legal case that happened in 1925 between the state of Tennessee and John Thomas Scopes who is a substitute teacher in a high school. Butler Act is a legal act that banned the schools from teaching the evolution of human science.

Scopes was accused of teaching human evolution and he is completely unsure about it. This case was handled by two famous lawyers at that time. William J Bryan who is a 3 times resident candidate and Clarence Darrow for the defense another big-shot lawyer.

During the hearing, Darrow examined Bryan to explain the belief and the history of humans in the bible. Bryan accepted that many were miracles ad they don't have any reasonable explanation for what happened.

Also, he discussed Adam and Eve's story, raising a question if even is created using Adam's rib how Cain got his wife. This speech got claps from the audience and spoken popularly by the media.