One of the main, but perhaps underappreciated, reasons quackery thrives in the United States is that the states legalize it by licensing practitioners of pseudoscience as health care providers. These practitioners are placed under the regulatory jurisdiction of, well, themselves. I call the whole deplorable process Legislative Alchemy, and you can see all posts on the topic here. It gives practitioners an underserved imprimatur of state authority and leaves public protection from harmful practices to the oversight of those who are themselves engaging in the very same conduct. Each year, dozens of bills are brought before the state legislatures to establish initial licensure or, once that goal is achieved, scope of practice expansion.
Most attempts fail, but CAM practitioners are a dogged bunch, and they will come back each year until they get what they want. It took chiropractors about 60 years to become licensed in all 50 states. Acupuncturists are almost there. Naturopaths lag far behind, but are slowly gaining ground each year, even if it is only via practice expansion in states where they are already licensed. 2015 was a losing season for all, but not without advancement toward larger goals.