I was with you until the last paragraph. How do SLAPP laws intimidate people into silence? Their purpose is to combat the use of legal means to silence speech,

I was with you until the last paragraph. How do SLAPP laws intimidate people into silence? Their purpose is to combat the use of legal means to silence speech, so it seems the opposite is true. Further, if SLAPP laws did burden speech, then that would be a first amendment issue since they are enacted by states which are bound by it.