Earlier quoted context omitted.
Retailers can offer discounts for cash transactions, per the Durbin Amendment to the Dodd-Frank bill of 2010. https://en.wikipedia.org/wiki/Durbin_amendment
It depends on where you live. 10 states have laws that prohibit or restrict discounts for cash transactions: California, Colorado, Connecticut, Florida, Kansas, Maine, Massachusetts, New York, Oklahoma and Texas. Some of those restrictions have been invalidated by federal courts, but I was somewhat confused about which states were affected.
I imagine it's because of lack of enforcement?