Oh right I forgot about the further point proving Ulfric's dictatorship.
Its not dictatorship, theres still a spoy for any jarl to step forward. What the post was talking about was that no one has a chance because of ulfrics actions. Ill give an example-someone comes along and ends world hunger and finds a way to legally get rid of taxes while at the same time find a way for govt to generate revenue. That person is running for president. Because of all the things that person does, no one is gonna be taken as an opponent or be able to wrestle that president spot from said peraon.
Theres a spot for aomeone to run against him, but its basically not smart because theres no chance at this poiny. Its not because of fear or threats, its basically a question that will ne asked. "i freed skyrim of the empires influence, I am in the process of strengthening our land, and planning on invading the thalmor. Also I have the dragonborn who backed me up and fought for a free skyrim which by my actions was set in place. Sooo what have u done that the people of skyrim will chose u over me?".