I disagree. The blame lies mostly on the Left. According to your argument, things like the post-Seattle movements never should have happened, because "we" had already been defeated.
I've been an activist for 20 years. The biggest foe we fight is our own fear and self-doubt. If it isn't the paranoids in our ranks ranting about COINTELPRO and police surveillance, it's the leftist doomsayers telling us why history is against us. Our biggest barrier is our own excuse-making for our inaction.
This is what I call Calvinist leftism: a profound faith that we suck because historical conditions are against us.
I stopped being a Lutheran many years ago, so I'll argue that we can achieve fundamental social change if we put our collective minds to it. Look at what the right did over the past 30 years. If they can do that, we can certainly do something similar and better.
Don't accept the facts and limitations. Move the goalposts, dammit!
Chuck0