Nothing good comes from political violence, period.— Jamelle Bouie (@jbouie) June 3, 2016
Jamelle later makes important exceptions for violence against violence ('just wars') and political violence in in absence of democratic political structures (protesting a dictator, for example).
But even in the presence of democratic, nonviolent methods of political change, condemning each particular riot individually isn't quite the same as condemning the existence of riots and violent mob justice in the abstract.
I think 100% of the violence we've seen this election cycle has been bad, and it represents the worst example of unthinking tribalism. These factions aren't doing their candidates any good, and in general nonviolent, rational discourse is super-effective at getting stuff done over the long-run.
But even I can see that these riots have provided useful information to the world about Trump's status as a broadly acceptable public figure worthy of becoming president. This hints at a deeper, possibly virtuous justification for occasional political violence.
Interfluidity, writing about the 2015 Baltimore riots, beautifully captured the social logic of why the abstract threat of mob violence might be helpful in keeping society functioning smoothly:
Anyway, I interrupt your punditry to tell you that all your commentary about riots is bullshit and confused and tendentious and fuck off. And that economists, God bless ‘em (no, not really), have a name for this.
Politically motivated riots are a form of altruistic punishment. Look it up. Altruistic punishment is a “puzzle” to the sort of economist who thinks of homo economicus maximizing her utility, and a no-brainer to the game theorist who understands humans could never have survived if we actually were the kind of creature who succumbed to every prisoner's dilemma. Altruistic punishment is behavior that imposes costs on third parties with no benefit to the punisher, often even at great cost to the punisher. To the idiot economist, it is a lose/lose situation, such a puzzle.He continues:
Altruistic punishment is not tactical, it is emotional, and it is sometimes but not always functional. It functions, sometimes, to change expectations about what is possible or desirable or acceptable. In economist words, people’s propensity for altruistic punishment changes the expected payoffs associated with nonaltruistic behavior by those punished directly and, more importantly, by third parties who observe the unpleasantness. Changes in expected payoffs change the equilibria that ultimately prevail, in ways which may be beneficial for some groups or for “society as a whole”, however you define the welfare of that entity.His key insight:
Riots do severe, immediate, harm, they are an escalation, they are violent, they are prima facie bad. Yet the fact that rioting sometimes happens, the uncomfortable possibility of it, has historically and may again create urgency and motivate political change that is ultimately good.Last one:
[H]uman affairs would be intolerable without altruistic punishment. In small matters, the fact that people will bear disproportionate costs to protest small ripoffs is essential to the integrity of everyday commerce. In larger affairs, the human propensity to altruistic punishment means we all bear costs of perceived injustice, we all have a stake in finding some mix of society and legitimating ideology under which outcomes are perceived as broadly right.
Or maybe you should just read the whole thing.