Upon demobilisation, Robson returned to his political career. His long absence during his war service had put pressure on his marriage and ended when his wife divorced him in 1947. He remarried soon after to Naomi Priscilla Gee at St Peter's Anglican Church,
Watsons Bay on 9 December 1950. During his military service he had missed the political upheavals of the collapse of the UAP and the foundation of the
Liberal Party in 1945. He retained his seat at the
election on 3 May 1947, assisted by a young
Robert Askin, a former Sergeant in his battalion. Robson retained his seat again with 67.39%. He later supported Askin in his bid to enter the Parliament in 1950. He was returned again at the
14 February 1953 election unopposed. In August 1954, after the long-serving leader,
Vernon Treatt, announced his intention to resign, and now-Deputy-Leader Askin and
Pat Morton had tied in a vote to succeed him, Robson was persuaded by Askin to accept the Leadership of the Liberal Party as a compromise candidate. Like other senior members of the party, after having no conservative government since Alexander Mair in 1941, Robson had no experience in government, he had little interest in policy except for Cold War anti-communism, ignored majority views of his party and fellow parliamentary colleagues and further alienated party members by trying to forge a closer alliance with
Michael Bruxner's
Country Party. He was returned for the last time at the
3 March 1956 election with 71.41%. Robson, however, did not stay long afterward; on 26 July 1957, he resigned his seat, and returned to his legal practice until he retired. ==Later life==