Answer
No, Kārlis Ulmanis did not have any direct successors. He was the Prime Minister of Latvia from 1918 to 1920 and again from 1934 to 1940, and was the country's first President from 1936 until his death in 1942. After Latvia was occupied by the Soviet Union in 1940, Ulmanis was deported to the Russian SSR, where he died two years later.