The problem of authority delimitation between several branches of government exists in all countries worldwide; however, this problem is the most urgent in the USA, because there is no clear delimitation in the Constitution of the country. The legislative and executive authorities used quite vague constitutional language at different development stages of American State and that branch of government, which was stronger than the other one, won. For instance, in the period of Washington, Jefferson and F. Roosevelt rule, the executive authority interpreted in their own benefit that Constitutional premises, which were devoted to military and foreign policy Presidential and Congress powers. At that time, in the last quarter of XIX and in 20-30s of XX, the victory was on the Congress side, as the state was governed by the "weak" Presidents. Because of long fight between the executive and legislative authorities, two approaches were formed - strict and loose construction of the Constitution of the USA.