Why did the framers of the u s constitution want the states to maintain significant power as a part of the federal system?

What was a major cause of world war i?

What impact did entry into ww1 have on life in the us?

How are the republican and democratic presidential candidates chosen? a. they are nominated by their state governments. b. each is nominated by his or her respective party. c. each is chosen by the governor of his or her home state. d. they are chosen by the house of representatives.