HIV/AIDS activists in the 1980s were critical of the Reagan administration was slow to act on the pandemic as it emerged.
Screening of donated blood for HIV/AIDS was not instituted within the United States of America until January 1985.
Let's imagine that either in 1981 during surgery after the assassination attempt, or during his colon surgery, if it's brought forwards from it's OTL date of July 1985 happens earlier before the screening is introduced, that Ronald Reagan receives blood which is contaminated with HIV and contracts the disease.
How does this change:
1) The Reagan administration's response to HIV/AIDS?
2) Societal attitudes toward HIV/AIDS?
3) National opinion of Ronald Reagan, particularly among his conservative Christian base.
4) Anything else you would care to mention?
Who says you'd even know he contracted HIV? There are rumors, spurred on by his own son, that Reagan even had problems with Alzheimers during his presidency. The joke is that when Reagan, under oath during Iran-Contra, said "I don't recall" that he was actually not being evasive, he was telling the truth! In 1987 Baker became Sec of State, he was told upon taking office by the outgoing staff that Reagan had become distracted, disoriented, and uninterested in the job to the point that Bake should consider that the 25th amendment may need to be invoked if something major happens so Bush could be in charge. Luckily, I suppose, Reagan was in great fashion, mood, spirits, and intellect when he met with the staff at their first meeting when they all decided to watch him extremely closely for signs of a problem. (This all according to Edmund Morris, Reagan biographer).
So basically my opinion is that if he got HIV, I doubt it would be made public, and he doesn't run for a second term if he catches it in 1981, he's dead by 1988. If he does run for a second term, good lord even all the best medical attention of that Office isn't going to do all that much in the late 1980s considering the amount of stress and lack of sleep he's going to have. Not to mention all the handshaking and people with germs around him. He's dead by 1985 or else the press starts putting 1+1=2 together and THEN it's out of the bag with him having AIDS, not just HIV. By then he's been looking terrible, not his high spirited self for quite some time, the public probably hasnt seen much of him, and he's not the "teflon president" that he was in OTL. He isn't impeached or forced out with the 25th but the public makes it clear he has to resign, possibly even joint non-binding resolution in favor of him voluntarily resigning. Does he resign? He was never keen on giving Bush a lot of power or responsibilities. The 25th was never invoked during the 1981 assassination attempt, and despite some saying he "intended that it be invoked" he never actually signed the letter invoking it during his colonoscopy, he only signed a letter saying he was "mindful" it existed. Well, yes, we all know that the 25th exists, but you have to say you're using it, if you're going to use it. Reagan could push us to a Constitutional crises.