Saragat entered the PSI Directorate in 1925, but the next year he went into exile, first in Austria and then in France, to escape Benito Mussolini's fascist dictatorship. Saragat returned to Italy in 1943 to participate in the Resistance and was arrested in November 1943 by the Germans but escaped. He became minister without portfolio in the Ivanoe Bonomi government in 1944. In late 1945 Saragat was appointed ambassador to Paris and in 1946 was elected to the Constituent Assembly, becoming its president.
In the chaos of Italian politics unleashed by the Cold War, Saragat's vision of democratic socialism clashed with the decision of PSI leader Pietro Nenni to keep the party allied with the Communist Party. In January 1947 Saragat broke from the PSI and established his own party, which eventually became the Social Democratic Party (PSDI). This new political force developed a pro-Western political orientation, allied itself with the Christian Democrats, and entered the government, yet it remained a minor—albeit important—element of Italian politics. During 1954–1957, Saragat served as vice premier in the Mario Scelba and Antonio Segni governments.
The PSDI remained at odds with the PSI until the end of the 1950s. After 1956, however, the two parties began a rapprochement that culminated in a temporary reunification during 1966–1969 and the so-called Opening to the Left, namely the return of the PSI to the government and in its gradual detachment from the communists. Saragat's 1964 election to the presidency was a symbol of this new political climate. After his term expired in 1971, he became a life member of the Italian senate. He died in Rome on 11 June 1988.
Di Scala, Spencer. Nenni to Craxi: Renewing Italian Socialism. Oxford: Oxford University Press, 1988.