Ag-gag laws are clearly unconstitutional. They put the interests of corporations ahead of the interests of the people. The laws make it "illegal" to uncover the truth. It is impossible to imagine any interpretation of the First Amendment in which it is illegal for citizens to tell the truth in public. These laws should be repealed immediately.
If there is misconduct at a slaughterhouse that compromises the safety of the peoples food then I think the people have the right to know and should know about it by any means. Preventing someone from doing that could be construed as unconstitutional because it could violate freedom of speech.