In a land where you cannot be jailed solely on the basis of what you say, where everyone has access to the political process and all are eligible to vote and to run for office, peaceful revolution is not "impossible in the US". It has happened before (MLK's civil rights movement) and can happen again.
Peaceful revolution, however, is unable to take place here:
Egypt Erupts: Arab Spring cradle seethes with fresh unrest - YouTube
A Weekend Of Violence in Cairo - Image Gallery - YouTube
To equate what's going on in Egypt at Tahrir Square to pepper spray at a college campus is just insulting.