Throughout the course of human lives, there are none that have not met a single person they despised. There are as many ways of handling these people as there are despicable people in this world. However, there are a few methods I would like to discuss.
The first among these is violence. Some will immediately resort to this whenever faced with unsavory individuals. However, this is not the best way to handle them due to a minor complication- the law. As such, violence should only be used when one is under legal grounds to do so- when laws regarding self defense are applicable, and the other party is terrible enough to come forward with intentions to physically harm others.
Another very common method is to argue, whether it is through the form of protests, slander, or even formal complaints. While this has worked in some cases, often times it breaks down into violence, examples being the revolutionary war, and a small portion of the BLM protests. Often times, if you truly believe someone to be that bad, they will not listen to reason. This makes arguing often a bad idea, as it strains relations and may also break down into violence. People may also claim that you are morally bankrupt if you try to argue with them-it doesn't make sense, but they're just going to do it.
Now, this next idea is my favorite of all- just leaving them to their own devices and not messing with them. You see, chances are, unless you are the most ill tempered person you know, other people will have the same ideas as you. One can simply do nothing, and leave the shouting, arguing, and fighting to those who are more easily angered. If someone is truly terrible, the rest of society will punish them in your stead, whether through social exclusion, gossip, or someone else fighting them instead of you. This way, you need not put yourself at risk-no problems with the law, no rumors about you being temperamental, nothing. Just leave the insufferable people be.
The only times I would not utilize the third method and leave them alone, are when the opposing party decides to do something serious to you and gives you legal and moral grounds to defend yourself. If they come to try and hurt you, call the police, run, or defend yourself. If they claim overly horrible things about you, sue them for defamation of character.