Tucović devoted his entire life to fighting for workers' and human rights, gender equality, universal suffrage, social justice and civil liberties in the Kingdom of Serbia.

[2][3] He was already an adherent to socialist ideas when he came to Belgrade in 1899 to finish high school after previously spending six years in Užice.

[4] After coming back from Berlin, he gave up on his doctorate and started spending his time in socialist and labour movement, as a secretary of the SSDP.

He participated at the International Socialist Congress in Copenhagen the same year and gave an important speech criticizing the position that Austrian social-democrats took on the national issue, especially the Austro-Hungarian annexation of Bosnia and Herzegovina.

In a debate with Karl Renner he pointed out the colonial-enslaving politics of Austro-Hungary and the fact that social-democrats were supporting the government on the issue.

[8] Writing of the massacres of Albanians during the Serbian takeover of Kosovo from Turkey (1912), he stated: We have carried out the attempted premeditated murder of an entire nation.

In 1915, Leon Trotsky wrote about the political impact of his death: How many harbingers of the Balkan Federation have fallen in the wars of the last years!