I would hope some laws also affect your political setup, or else how is a Democracy different from a Dictatorship? Clearly you can change from one to the other:
It'd be a shame if that process is just: You are a Democracy. Vote in the National Socialists. Wait for a random event. You are now a Dictatorship.
Cleary you are not reading the Dev diaries, you can influence your and other country's political set up via esponainge.