"The only thing necessary for evil to triumph in the world is that good men do nothing." --Edmund Burke
By Barry Rubin
Ideally when the leader is going to be murdered the masses stand up and say, "I am Spartacus." In reality, particularly in countries with anti-democratic political cultures, it doesn't happen that way. Even if the four moderate parties do well in elections they still have to cooperate, having to face a wave of Salafist violence, too.
Now if the Tunisian army were to stage a coup that would make a difference. But what do you think would happen if the generals went to the U.S. embassy and asked for America's support to overthrow the Brotherhood? In Egypt, we do see a sort of uprising against the regime. But without the army's support it doesn't seem to have a chance of taking power. Still, one must keep an open mind and see what happens.
Update: The leader of the Tunisian Muslim Brotherhood has now attributed the murder to certain forces that want to destroy Tunisian democracy. This statement is intended to make supporters blame the United States, Israel, and/or Saudi Arabia. Once again this situation shows how the Brotherhood will never suppress or punish the even more radical Islamist forces (Salafists) that it finds so useful both politically and to use their violence for its own benefit.