What are your thoughts on the backwards, “de facto” application of the Furman Court holding?

Discussion question for CRM 321 Substantive Criminal Law CRM-321-OL02

First, what are your thoughts on the backwards, “de facto” application of the Furman Court holding? Should the law ever be ‘retro-active?’ Second, consider why these changes were made. Is the Supreme Court the only perspective that matters, or are they actually influenced to a great degree by public perception? If they are not influenced by the public, then did they simply make a mistake in Furman? What do you think?