theoretically, as long as people have the leader(s) that will lead the country and as long as the said leader(s) and people have the firepower to back them up, yes we can, even in this day and age. will we or not, that's another question.
I like how in Greece and France, the people are not happy they can shut down the entire country, and then the goverment listens.
now, see, that seems sufficient enough. considering that the main, or one of the main, causes for revolutions is people unhappy with the government and want the government to change the things they are not happy about, i think this model is as close as we need to come to revolution these days.