it would be a fun concept if your colonists would actually do something to hurt the government of your colony if you did not stop them from protesting. my idea is that if they protest for too long, they will start destroying buildings and eventually revolt against your government. if this happens, your politicians will die, and some government policies will need a vote. this means in order to, for instance, tax the colonists, you will need to put it up for a vote, and then the population will decide whether they want a tax or not. the only way to reverse the effects of a revolution is by gathering enough support among the population ( by using a new resource called propaganda papers), then try and start a coup. the more support you have the more likely you are to succeed.
or more simply