Thanks for your thoughts here! This is a good dialogue I think. Here are mine...
As for the radical flank and Overton window theories. There is truth in this, no doubt. But I think we on the left overstate the case often, and without much historical evidence for our position.
Example: we often say, "oh the only reason MLK was effective is because white people were afraid of Malcolm or the Panthers!" And we say that as a way to suggest we need to be more militant in order to force the political elites to, once again, at least make the reforms that a slightly more moderate figure, like a King, would support.
The problem here is, it's actually wrong. Malcolm was dead by Feb 1965. And the Panthers didn't exist till 1966. There is no evidence his or their existence had anything to do with passage of the Civil Rights Act or Voting Rights Acts. Indeed, by definition the Panthers couldn't have, as they weren't around yet. What DID help with that was the violence of white racists in response to non-violent civil disobedience in Birmingham, Selma (and prior to that during the Freedom Rides, etc). In short, the movement moved the window NOT by its radicalism, actually. It moved it by its well thought out tactics, drawing the over-reaction and violence of the state. That does not bode well for an analysis that says, in the present, hey., let's break windows and burn courthouses to move the Overton window.
Now, true enough, the uprisings of 1967 and 1968 DID produce pressure for the Fair Housing Act of 1968 (as did, sadly, the assassination of King itself). And John David Skrentny's work on Aff Action legislation shows they also probably provided the impetus for some of the early aff action programs implemented during the Nixon years. So perhaps one could say, "aha, see, that moved the window!" But the problem is, a) the Fair Housing Act didn't even have enforcement teeth until 1988, so it wasn't very helpful for 20 years, and b) the backlash to those uprisings and the way the right controlled the narrative coming out of that period, led to the next 20+years of right wing governance.
This is the dilemma: when the left tries to move the Overton window with actions and tactics like that -- however justified they can be, and I said do explicitly in my initial piece-- the reaction from the right is what actually moves the window...further to the right. That has happened every time, without fail.
Another problem with the theory is that it ignores how the right moved the window mostly in the last couple decades (other than just riding the wave of backlash to the 60s). They didn't do it with protest activity. They did it with narrative, with story-telling, with laser-focused media (talk radio, etc). THAT is how they moved the country to the right. To think that we can move it left with protest, property destruction and saying "fuck" on a placard, or flipping off cops is juvenile horseshit. Now I realize the left doesn't have the same tools as the right, to the same degree. But the idea that we have nothing but the streets -- no power in community organizing, no ability to create strong alternative media, etc -- is nonsense. It's a choice we make because we fetishize protest as the only real kind of activism, or at least we too often do. And yet we haven't really studied past protest mvoements and understood what made them work and what didn't.
Additionally, if you think about the areas where the left has had some success moving the Overton window, you'll see the accuracy of my argument here. What are the two biggest examples in recent years? First, LGBTQ equality, and second, health care. Even a decade ago, marriage equality (granted, only a small piece of the larger liberation pie) was going nowhere. So too, in general, the culture was far less supportive of the movement than now. Likewise, a public option for healthcare, let alone single payer, was dead in the water. Now, both of these issues are far further along. How did that happen? Not becuse activists were being particularly radical on either issue. It was pretty mainstream organizing, politifcal campaigning, and personal connections made by folks coming out (as for the LGBTQ liberation issue), and people actually being impacted by things like medical bankruptices, etc. All of this means to the extent it is vital to move the window -- and I agree it is -- there is no reason to assume the best way to do that is with protest per se, let alone protest involving breaking windows.
As I said, there's no reason to shame or attack folks for releasing legitimate frustrations, and I am not. But recall, in my piece I noted that most of the questionable tactics were manifested NOT by the most oppressed community members but by wannabe anarchist white folks who enjoy breaking shit just to break it. It wasn't movement folks even doing most of that stuff. To elide that fact is dangerous for the movement. And I see no evidence or logic to suggest we should be making common cause with everyone who engages in those tactics either to move the Overton window, or because the enemy of my enemy is my friend, or anything else...