temporary suspension of my policy not to engage you, because you raise an incredibly important point for all those claiming a revolutionary politics (and I'm not saying you do or don't):
in every one of those cases, it was an attempt to conduct a revolution by the ballot box. And soon a large chunk of the o-called "pink revolution" will fail.
When people get squeamish about historical examples of bloodier revolt, this has to be the response to them. You cannot have a revolution until the fundamental social relationships of that society are altered for the longer term!. Chavez tried to prove--valiantly--that it could be done.
But the reality is that you cannot permit the old power to retain their wealth and standing and expect to achieve revolutionary goals. In every case you mention--and several more--the rich were permitted to retain their property, most notably their control of the media, which is turning out to be pivotal. So it's been years of manufacturing one material crisis after another, and then having your media outlets blame the revolutionaries for the crisis. Over and over and over again.
No one can stand up to that for years on end. No one.
So if you want a deep change in the US, pay close heed to these roll backs. They've worked here, too, with civil rights gains and other social progress being rolled back for the same reasons.
Sorry for the interruption.