After world war too hate speech is almost prohibited in all "civilized" countries. However there are 3 targets can be used without consequence: wall street bankers, politicians in Washington, rigemes usually are inferior in morality. The first 2 targets are virtual targets so they are used in election frequently. Not showing fighting spirit create personal identity by fooling people is a recipe for failure. Many politicians use the technique. Example: Rubio, Hillary, etc. China, Russia, are good target for boost support in election to show a fake hero image
Hate is human nature from evolution because human , not like any other species, were evolved not only from other environmental pressure but also from war and killing each other. It boosts the fighting capability of a tribes and promote consolidation. That's why it exist at first place. War is also part of human nature. To find excuse to attack others , creating evil is a good way to get public support. Western journalists are doing this job very well by distorting the reality and mix their interpretation into selected facts in a very deceptive way. All the direct and proxy wars in last 20 years (Except Afghan) are approved by public because of their work.
A good study of the topic should get nobel peace price. However, noble prize commitee itself has the same mentality as western journalists. A lot of winners a fake hero based on face value of commitees perception that eventually create more confilicts in the world.