I know that without unions workers get squeezed like sponges. I also know that unions have a bad reputation after being infiltrated by mobsters/mafia.
After reading carefully the materials available on the AFL-CIO web site I still do not understand how a secret vote would harm worker's right to form a union.
It seems to me that in fact it would only harm the power of the union leaders over their members. But I might be wrong - if you have a simple example to illustrate how this works (even a fictional one), please illuminate me.