Who is the Republican Ron Johnson?

http://thinkprogress.org/health/2012/06/28/508299/ron-johnson-cancer-patients/?mobile=nc

http://thinkprogress.org/politics/2010/07/10/106491/petri-ron-johnson/

http://thinkprogress.org/politics/2010/09/28/121315/ron-johnson-child-abuse/

http://thinkprogress.org/health/2012/04/02/456480/ron-johnson-doesnt-know-rate-of-uninsured-in-home-state-of-wisconsin/

http://thepoliticalenvironment.blogspot.com/2012/07/limitless-self-absorption-of-sen-ron.html