A lot of people blamed AIDS on homosexuals, who weren't exactly a popular group in the 1980s. An antiquated name for the disease, and one that sounds more like a death sentence than even AIDS, was GRID, which meant "Gay Related Immune Disease." Given that IV drug users also were lumped in with AIDS, you have two groups of people society wasn't big fans of who were linked with the disease, so simply putting Carter or HW in the White House won't cut it - you would need an acceptable target for the disease or a high-profile straight person to get it in order to make it a cause celebre. Sort of like how Magic Johnson brought new light to the disease.