During the October Revolution of 1917, he was a member of the Moscow Military Revolutionary Committee, a member of the Presidium of the All-Russian Central Executive Committee and the Supreme Council of National Economy.

From 1922 he was a member of the Anti-Religious Commission under the Central Committee of the All-Union Communist Party (Bolsheviks) and head of the Secretariat for Religious Affairs, since 1929 he was Chairman of the Standing Commission on Cults under the Presidium of the All-Russian Central Executive Committee.

[2] Smidovich was the leader of the communist organization Komzet, which was established in 1921 in Russia.

[3] The idea to found a Jewish Autonomous Oblast in the USSR with Yiddish as its official language belonged to Mikhail Kalinin and Smidovich.

The urban-type settlement of Smidovich in the Jewish Autonomous Oblast is named after him.