Paul, I have two questions for you:
1. Doesn't your dismissal of revolution (of some sort) as an actual option--based on people in the US being relatively well fed, clothed, with access to particular privilege, etc. -- doesn't this just displace the revolutionary justification to outside US borders? This is what's called the "third worldist" hypothesis in revolutionary theory, which argues that we have a "labor aristocracy" in the 1st world that makes it impossible to instigate revolution or real (positive) world change of any sort. I mean, I disagree with this (on an empirical and anecdotal basis, since I am from one of the many parts of the US that are basically abandoned zones, "wastelands" of the type described by Chris Hedges in his recent book--and these areas are larger and closer than liberals like you make it seem). But still, do you think that revolutions (including against US Imperialism) are justified overseas, but just not here?
2. I think you're misportraying the revolutionary argument about historic change -- the idea isn't that there are there massive "jumps" that occur after revolutions (if anything, every revolution begins with a material step BACKWARD as people rebuild from the revolutionary war). The argument is that revolutions are necessary points of abrupt discontinuity, where that graduated, snails-pace of actual historic movement CHANGES TRAJECTORY. At certain points this change in direction involves a (relatively quick) restructuring of "productive forces." Today that would mean, for example, the immediate start of a process toward entirely dismantling coal and oil energy networks, paired with massive projects to build up new energy sources and decrease/redistribute existing productive capacity throughout the world--including more localization of agriculture. All of this comes through ABRUPT breaks in political power--breaks in which people directly assert themselves, which often means some degree of violence against the police/military/pinkertons/etc. suppressing those people and against the material conditions (such as prisons, military installations, sweatshops, etc.) aiding this suppression. It doesn't mean there is some magical "jump ahead," just a kind of torsion which changes the ultimate arc of history.
So do you actually think you have historical examples which contradict this (the actual) revolutionary argument? If so: WHAT? What real basic changes in productive forces or fundamental social relations actually came out of simple slow growth with no abrupt discontinuity in trajectory, with no people directly rising against injustice and (often violently) destroying it?
I also want to point out that I think much of your portrayal of Obama (and even his differences with Romney) is inaccurate even according to the liberal-progressive metric you seem to be using. Here's more data on that in the best (that I've read) of the "progressive" critiques against Obama by Matt Stoller:
Finally: Though I don't think it's reasonable that you offer a straw-man argument for revolution here, I also want to emphasize that I have little interest in defending the particular revolutionary arguments of World Can't Wait -- an organization which is simply a front-group for the wingnut RCP Bob Avakian cult. But if you're looking for a straw man to burn, they're a goddamn good one.