1. The Constitution.
2. Yes of course. States should have some of their own say in state government because this allows for a diverse set of areas for people to settle into. Settlers can pick and choose which aspects of government they want to be ruled under.
3. I don't know who ur governor is
4. The similarities, responsible for determining the laws and protections of U.S citizens, differences, governors have to decide what's best for their state not always the country as a whole.