Final answer:
The National Rifle Association (NRA) predicted that Walmart would lose business over its stance on gun sales, emphasizing the NRA’s defense of Second Amendment rights.
Step-by-step explanation:
The group of supporters of gun rights that predicted Walmart would lose business to other retailers, "who are more supportive of America's fundamental freedoms," is the National Rifle Association (NRA). The NRA is known for its strong advocacy for Second Amendment rights and often opposes legislation that restricts the sale or distribution of guns and ammunition. Over time, the NRA has evolved from a sports organization dedicated to marksmanship to a powerful interest group influencing political candidates and defending gun rights.