One of the most powerful reasons that the South Carolina legislature has done an about face and voted to take down the Confederate flag, is that one of the nine people murdered by a flag touting white supremacist was one of their own, a state senator. Many of those legislators attended his funeral at the church where the shooting took place and some discussed that experience in the debate of the matter on the floor of the legislature.
Legislators are by nature social animals and the identification with a murder victim who was one of their own crossed party lines. What I call the "present company excluded rule" is the principle of etiquette and social interacts that considers it rude, to the point of being socially prohibited, to insult or be openly hateful towards someone who is part of your social circle with whom you regularly interact.
This murder brought home to state legislators in South Carolina that their persistence is keeping up the Confederate flag violated this rule as to people within their ranks, and not mere outsider citizens, and acted accordingly.
Similar observations can be applied to gay rights. For example, it is no coincidence that the laws in Colorado favorable to gay rights were almost all enacted while the Colorado General Assembly has openly gay legislators and in many cases those legislators were the sponsors of the bills.