When I become the leader of Mars (assuming Mars at this time is self sufficient), there will be no government. I'm assuming that the Mars population before I die will be no more than 1000, so no government is needed, we can all just come to consensus. We will all be useful people, and provide food to put out on the market, goods, and other services. Food and other necessities will be free, in fact, nothing costs anything. You want something, you get something. However, to make things fair, we must all contribute to society. You ask for a pair of shoes, someone makes shoes for you, and you grow crops for them, something like that. Friendship! The scientists back on Earth will send us monthly supply of necessities like new technologies, inaccessible resources, and perhaps new people once in a while). Then after the gravity issue is solved and we can start naturally reproducing; and after we become fully self sufficient, then we will declare our independence from Earth. I will give a famous speech that everyone on Earth will watch, and I will say something like "Screw you Earth! We don't like you anymore! You can die from global warming on your own!" We will cut off all supply from Earth (few exceptions), and officially be known as Martians.
After I die, we will remain isolated, and a small progressive and democratic government will be formed just to keep things on track. After the population hits 5000, the birth limit will be 2, stabilizing the population. The government's only job is to advance the society, hearing the wishes of the people, and reacting appropriately with a popular vote of over 75%. The society from the start will be all good people (thanks to me), so from the start, there will be no bad people. After the 5000 cap is hit, then a new city could be formed, 250 km away, with it's own government. The two governments will not work together, but will communicate their progress. Remember, the people have actual control here, and the government is here to only collect the public census.
This cycle will continue, and soon enough, but, we must remain the same species, so to avoid variation due to lower gravity, everyone will be wearing pressurized suits for the most part, and working out regularly.
What will you do if you become the leader of Mars?