He was elected to the Norwegian Parliament in 1862, representing the constituency of Smaalenenes Amt. He was a farmer there. He was re-elected in 1865, 1868, 1871, 1874 and 1877.
By the last term he had become bailiff (foged).
When the cabinet Sverdrup assumed office in 1884, Sørenssen was brought in as a part of the executive branch of government. He was appointed Minister of Justice and the Police on 26 June.
He left this position exactly one year later, having in the meantime served as Minister of Labour from 17 February to 4 March 1888.