Unlike Wise People throughout history, I think that anger is good for something. Every emotion we have, evolved for some purpose, and the humans who felt it were more likely to pass on their genes than the ones who didn't. I believe anger is no exception.
That doesn't mean, however, that it's just as useful as it always was. A lot of things have changed in the last few decades, and it's unlikely that evolution has had time to catch up with all of those changes. So, it's worth looking at what anger is good for, in order to have a better handle on when it's no longer useful. So, what does anger do for us?
Well, I'm no expert on human psychology, but it seems to me that anger is mostly good for suppressing other emotions. Fear, pain, weariness, all can be ignored a lot better when you're angry, than when you're not. Even mostly positive, desirable emotions like joy and contentment are not as good at making you ignore pain, weariness, hunger, thirst, and anything else you need to temporarily shrug off in order to get something done (like, perhaps, fight off the attack of a wild animal).
It's not hard to see why this might have been important to our ancestors. Somebody whose family is under attack, needs to have that burst of rage which allows them to fight off the threat, in order to at least allow for a safe and orderly retreat (or perhaps even send the attacker running). If you thought all you needed was love, you might find that the loving family members, who cannot muster anger but still feel fear, all go sprinting for their lives when a predator comes near. We need fear (the truly fearless don't live long enough to have kids), but we need to occasionally ignore fear, so we need anger as well. But, really, how often do we need to fight off a predator nowadays, here in the advanced economies of the world? I won't say never, but clearly not as often as before.
After a certain point in our history, of course, and probably even our prehistory, the most likely predator to come attacking was another human. So, anger suppresses something else: it suppresses empathy. If one side in a fight is still feeling the healthy and moral "ick" factor about hurting another human, and the other side has suppressed it via anger, then you can make a pretty good guess which side will still be alive to pass on their genes (and values). We need empathy, in order to live together in groups, but we needed to occasionally ignore empathy (when predatory humans try to kill or enslave your family and friends), so we had (and have) anger. If you're living in an area where this is still a not uncommon occurrence, you probably still need it. But, really, how often do we need to fight off a band of raiders nowadays, here in the advanced economies of the world? I won't say never, but clearly not as often as before.
When we mostly feel anger nowadays, here in the advanced economies of the world, is when we are arguing. This probably always happened, but we had other emotional responses to rein that in. Primarily, we could see the facial reactions, and hear the tone of voice, of the people we were talking to, and this often (not always) helped us to reduce the anger and revive the empathy. This would be especially true if you know the other person well, and thus could interpret their facial expressions and tone of voice especially well.
Now, however, we often interact in ways that still stoke anger, but without any of the ways we used to have to rein that in. Road rage was the first widely recognized problem with not being able to see and hear the other person; what glimpses we have of the other driver are fleeting and not detailed enough to trigger any of the empathic responses that might balance our emotions out. Online communication is, famously, even worse for this problem.
Even if we acknowledge that anger is sometimes useful, for all the reasons above, it is particularly ill-suited for online discussion of non-physical conflicts, such as political ones. There's no physical pain that needs suppressing, and no advantage in suppressing empathy for the other side. In fact, the very fact that the angry person has lost empathy for their "opponent" probably hinders their own cause, since they can no longer anticipate their opponent's next move, or understand the appeal of their opponent's arguments in order to undercut it by a well-targeted response. Mostly, it devolves to shouting.
But the biggest problem with a political process motivated by anger, is that after the election (or court case, or referendum, or whatever), even if you win, you will not have sent the object of your anger into retreat. They're still there, living next to you, or at least in the same polity (town, state, country). All you've really done, is convince them, and yourself, that they are the "other", for whom one should not feel empathy. But, we need empathy to live together.
This being the case, we need a better way to rein in anger, in those cases where it is maladaptive. Hectoring people about it will not help, nor will blog posts. The solution we need, is not yet readily apparent.