sec1
1. the framers of the constitution clearly did not want a British form of govt. So the decided on a form called federalism were the power of the govt. would be limited and equal among the states
2.the national govt has delegated powers. these are powers granted  solely by the constitution. the include expressed, implied, and inherent powers.
sec2
1.the constitution requires that the govt.  guarantee each state a republican form of govt. The constitution and the supreme court doesn't define what that  means but it is understood to mean a representative govt.
2. Federalism is a dual system of govt. Two basic levels operate over the same people and territory at the same time. this undoubtedly causes tension and conflict.
sec3
1.states can't enter into any alliance. They can however enter into interstate compacts among themselves and foreign states. more that 200 compacts are now in force and they involve many states.
2.the Privileges and Immunities clause states that no state can draw unreasonable distinctions between its own residents and other people who happen to live in other states.