| Preach to the choir|
|Crux of the matter|
|Speak of the devil|
|An act of faith|
Blue law is the US term for laws limiting retail activities on Sundays, including laws restricting or barring the sale of alcoholic beverages, or restricting or barring businesses from being open at all on Sunday. These laws originated in Christian tradition but are often maintained for economic or political reasons. "Blue" in this sense comes from a 17th century (or in the US, 18th century) usage meaning "rigidly moral".
The trend over the past few decades has been to repeal blue laws, although many still remain on the books. The strictest blue law still in effect is in (of all places) New Jersey. Bergen County, New Jersey contains a high concentration of high-end shopping malls, which attract shoppers from New York City taking advantage of lower state sales taxes. This has motivated residents to retain the county's law banning sales of just about everything on Sunday, despite many referenda to repeal it. The blue law is estimated to cost the county millions of dollars in lost business and sales taxes, but there's a compelling case to be made that keeping New Yorkers away for at least one day a week is worth it.
Some blue laws, such as those preventing automobile sales from being conducted on Sundays, were pushed forward not by religious groups but by local industry leaders, to give them a day off and ensure that none of their competitors would be open on that day.
In some European countries, particularly Switzerland and Austria, laws restricting Sunday trading have been supported by an alliance of religious conservatives, workers' rights activists (who are concerned that 7-day opening would lead to pressure on low-paid workers to work all 7 days) and small business supporters (as both countries exempt shops, etc., where there are no employees and only the owner or joint owners work there).
- National Sunday law: A Seventh-day Adventist conspiracy theory about Sunday blue laws in the United States.
- probably not; the NFL was only founded in 1920 and did not surpass College Football in popularity until after World War II