it guards against tyranny because in federalism the power is divided by the federal government and the state government. Not all the power goes to one person or group so the power will be split. Which that means that no one can do what they want with the power. It prevents all the power going to one person or group. :)
<span>it separates power, making it more difficult for any one government figure to seize control. If a portion of power is given to the states, it takes away from the central government. So, even if someone took control of the entire main government in DC, they wouldn't have total influence over all public policy. It's all explained in-depth in The Federalist Papers, mainly the ones by Madison No. 40-58</span>
