In his youth he adopted the political program of Ante Starčević and together with Vjekoslav Spinčić and Matko Mandić brought Croatian national thinking and sharp attacks against the local Italian party and Italian nationalism into the political life of Istria.
As a leading local politician, he fought for three decades for a renaissance of the region's Croats.
[1] He was one of the leaders of the Croatian national movement in Istria as well as a member of the Istrian provincial parliament from 1883 to 1914.
For one period he was ambassador to the Imperial Council in Vienna, then president of Starčević's Party of Rights.
From February to December 1920 Laginja was ban of Croatia within the Kingdom of the Serbs, Croats and Slovenes.