In the late 1980s, the government appeared to have many characteristics in common with Western, democratic political systems. For instance, a constitution established all organs of government and granted to citizens a series of political and civic rights. A legislative body, the Congress of People's Deputies, and its standing legislature, the Supreme Soviet, represented the principle of popular sovereignty. The Supreme Soviet, which had an elected chairman who functioned as head of state, oversaw the Council of Ministers, which acted as the executive branch of the government. The chairman of the Council of Ministers, whose selection was approved by the legislative branch, functioned as head of government. A constitutionally based judicial branch of government included a court system, headed by the Supreme Court, which was responsible for overseeing the observance of Soviet law by government bodies. According to the Constitution of 1977, the government had a federal structure, permitting the republics some authority over policy implementation and offering the national minorities the appearance of participation in the management of their own affairs.
In practice, however, the government differed markedly from Western systems. In the late 1980s, the CPSU performed many functions that governments of other countries usually perform. For example, the party decided on the policy alternatives that the government ultimately implemented. The government merely ratified the party's decisions to lend them an aura of legitimacy. The CPSU used a variety of mechanisms to ensure that the government adhered to its policies. The party, using its nomenklatura authority, placed its loyalists in leadership positions throughout the government, where they were subject to the norms of [[democratic centralism]]. Party bodies closely monitored the actions of government ministries, agencies, and legislative organs.
The content of the Soviet Constitution differed in many ways from typical Western constitutions. It generally described existing political relationships, as determined by the CPSU, rather than prescribing an ideal set of political relationships. The Constitution was long and detailed, giving technical specifications for individual organs of government. The Constitution included political statements, such as foreign policy goals, and provided a theoretical definition of the state within the ideological framework of Marxism-Leninism. The CPSU could radically change the constitution or remake it completely, as it has done several times in the past.