In 1912–1913, Kramer travelled to Condominium of Bosnia, Croatia-Slavonia and Dalmatia, establishing contacts with South Slavic political leaders in those areas of Austria-Hungary supporting the Yugoslavist goals.

In 1918, in the period leading to the dissolution of Austria-Hungary in the final days of the World War I, Kramer became a member of the Zagreb-based National Council of Slovenes, Croats and Serbs and its secretary for the Slovene Lands and Istria.

The council was an interim representative and legislative body of the South Slavs living in Austria-Hungary and it declared the short-lived State of Slovenes, Croats and Serbs independent.

He took part in establishment of the Temporary National Representation, the interim parliament of the Kingdom of Serbs, Croats and Slovenes.

[2] In the 1927 Kingdom of Serbs, Croats and Slovenes parliamentary election, Kramer won the parliamentary seat in the Assembly of the Kingdom of Serbs, Croats and Slovenes representing Ljubljana election district.