Moczar was heavily involved in the March 1968 events in Poland against Polish Jews, in which he led the faction of hardliners inside the Communist Party.

When Władysław Gomułka returned to power as the First Secretary of the Polish United Workers' Party in 1956, Moczar started to work for the Interior Ministry.

Lajos Lederer, a correspondent for the London Observer, called Moczar "a de Gaulle-type figure who is both an authoritarian Communist and a strong Polish nationalist."

Within the party, the enemy of the "Partisans" was the "Muscovite" faction: Poles who had escaped to the Soviet Union during World War II and then returned with the Red Army.

Some of the "Muscovites" were Polish Jews trained and supported by the Soviet Union who held important roles in the party and the secret police during the period of Stalinist terror.

He consistently built his image of a partisan hero, the symbol of which was "The Colors of the Battle" - Moczar's quickly filmed memories of the war, which had as many as thirteen editions.

For example, in 1965 he lamented the excessive frequency of Poles' visits to Western embassies while boasting that 1.5 thousand citizens are monitored by the ministry in connection with their contacts with foreign diplomats.

Moczar used the student uprising to initiate an anti-Semitic campaign, and he soon became a driving force in the 1968 purging of Jews from important party and government posts.

The Moczar-driven campaign of anti-Semitism caused a mass emigration of Polish Jews in 1968, most of which were government operatives and officials as well as doctors, professors, lawyers, or engineers.

However, Moczar had a hand in the December 1970 shootings in Gdynia, which resulted from Grzegorz Korczyński's assessment of the situation and recommendations in the striking Gdansk region.

He was a general in the Polish People's Army and held many high level posts in the government, serving as Minister of the Interior (1964–1968) and chairman of the Supreme Chamber of Control of Poland (1971–1983).