First of all, Khamenei died of novel coronavirus infection, and Iran is likely to blame the United States:
Now the news of novel coronavirus epidemic is everywhere in the world, especially many senior Iranian officials have become victims of novel coronavirus. Assuming Khamenei died in novel coronavirus, Iran would directly point the finger at the United States. The reason is actually very simple. At present, the Iranian government's financial situation is very difficult, and it has no power to organize comprehensive prevention and control of the novel coronavirus epidemic. The main reason is that the United States imposed sanctions on Iran, which prevented Iran from obtaining loans from the International Monetary Fund and purchasing more related medical equipment. If Khamenei died because of novel coronavirus, it was obviously because of the United States, so most Iranians would hate the United States even more and even launch more intense military action against the United States. Therefore, if Khamenei dies because of novel coronavirus, then the United States will suffer unprecedented Iranian anger. There is no doubt about it.
Secondly, Khamenei's successor must hate the United States if he wants to improve his reputation:
Let's talk about the internal situation of Iran. Assuming that after Khamenei's death, his successor wants to win the support of various Iranian political forces quickly, then the most direct way is to hate the United States, because it can attract the recognition of various Iranian political forces, and it is also a very simple way to shift people's attention to the United States, so that Khamenei's successor will reduce a lot of pressure.
Third, the power of the Iranian people will expand the momentum of hatred of the United States:
Khamenei is the religious leader of Iran. Once he dies in novel coronavirus, the Iranian people will think of American sanctions, so the power of the people will also make the new Iranian leader more hostile to the United States.