Revolution is impossible until it is inevitable
Because people forget that they need to have another idea in place before tearing the first one down. Otherwise, power hungry people are just going to fill the gap. You have be prepared. Have a new constitution READY, have a SOLID DECLARATION of what you're doing, have LEADERSHIP. If you want positive change, it has to come through planning and logic.
Define 'revolution'...revising the laws for more fairness or taking over government buildings?
Some people don't... more's the pity.