Here's a link to Assembly Bill 250 (AB250): http://nxt.legis.state.wi.us/nxt/gatewa ... ist&jd=top
It's a quick read so you can judge for yourself.
It's added expenses for the breeder. If I recall it'll be a fee to the State based upon number of dogs sold. Also a vet check & accompanying certification is required for each dog sold. I'm guessing the vets will give those services away free.
I can't answer the real question - who's behind it and what's their ultimate goal 'cause I'm not from WI & I don't know.