Kenneth McLean Baxter was born at Naseby, Otago, on 30 July 1893, the eldest child and only son of Theresa Reed and her husband, Robinson Wyllie Baxter, an Australian-born goldminer. His parents were strict Presbyterians but Ken was to become a lifelong atheist. He attended Naseby District High School until he was 14, when his father had a serious mining accident. Forced to find work, Ken became an apprentice compositor at the local weekly newspaper, the Mount Ida Chronicle. In 1910, with the encouragement of his parents, he moved to Dunedin to continue his apprenticeship with the printing firm Robertson, McBeath and Company.
The shaping of Baxter's political outlook had begun at home where his father encouraged him to read books by Jack London and others, which stirred his social consciousness. This process was accelerated in Dunedin before the First World War where Baxter listened to soapbox orators and joined the Otago Typographical Union. Andrew Walker, secretary of the union and later a Labour MP, acted as a mentor to the young Baxter and left him with a lasting commitment to the labour movement.
Baxter considered enlisting in the army at the outbreak of the war but instead joined the merchant marine. From 1915 to 1918 he served as a printer and first-class steward on the Niagara and other ships, and was strongly influenced by contact with militant seamen. He then worked as a printer in Sydney, where he associated with the syndicalist Industrial Workers of the World. By 1920 he was an ardent socialist revolutionary.
On 1 February 1919, in Sydney, Baxter married a 20-year-old widow, Neah Mary Brook Booth (née Griffiths). The Baxters had returned to New Zealand by March 1920, and lived for a time in Auckland before moving to Dunedin. Ken was an early member of the Communist Party of New Zealand, formed in 1921, and while in Auckland printed its first leaflet. From about 1923 both Ken and Neah were active in a Dunedin communist group, which met in their home. It was probably during this period that he earned the nickname 'Karl Marx' Baxter. They were also members of the New Zealand Labour Party, Ken of the Dunedin West branch, Neah of the Dunedin women's branch. The Dunedin communists formed a vocal left opposition within the Labour Party, criticising it for promoting class peace rather than class war; this led to their expulsion in December 1924.
In February 1926 Ken Baxter was convicted of selling seditious literature, but his sentence was suspended when he agreed to leave New Zealand. He had already planned to move to Australia because of his family's strained financial situation and Neah's poor health. In Sydney Baxter worked as printer for the Communist Party of Australia and attended its 1926 conference as a representative of the Communist Party of New Zealand.
In late 1927 the Baxters returned to Dunedin, where Ken worked as a printer at the Evening Star and was active in the Otago Typographical Union. While still close to the Communist Party it appears that he did not resume his membership. He was involved in several other radical movements, including the Militant Workers' League, the Workers' Defence Organisation and the New Zealand Section of the Friends of the Soviet Union. In 1933 he was expelled from the latter for activities that its communist leadership considered disruptive and contrary to working-class interests. While he later patched up his differences and held national office in the Friends of the Soviet Union, he had begun gradually to move away from his former political affiliations.
Influenced by reports of purges in the Soviet Union during the 1930s, and later by the Nazi–Soviet Pact of August 1939, Baxter became increasingly hostile to communism. These views were cemented in the late 1940s when he read Boris Souvarine's very critical biography of Joseph Stalin. For the next decade he was at the forefront of the anti-communist leadership of the New Zealand labour movement.
Baxter had been increasingly out of step with his communist associates in the trade union movement since the early 1930s. He believed militants should seek paid office in unions and not operate entirely through rank-and-file movements. In August 1932, now living in Wellington, Baxter was appointed secretary of the Wellington Typographical Union. He was committed to creating a single organisation from the various printing trade unions. In 1934 he played a crucial role in the formation of the Wellington Printing and Related Trades Union, of which he was elected secretary, and the New Zealand Printing and Related Trades Association, of which he became secretary-treasurer. In the late 1930s he strongly advocated the formation of a single national union of printers. This was achieved in May 1939; Baxter became national secretary as well as secretary of its Wellington branch.
Baxter was an active official, frequently travelling outside Wellington on union business. He edited the printers' federation journal, Imprint, in which he advocated rank-and-file participation in union affairs and urged action against war and fascism. He also put forward a strong case for a 40-hour week, which was achieved in 1937 despite strong opposition from employers.
Reflecting his own changing political views, Baxter succeeded in affiliating the Wellington printers' union to the Labour Party in 1936. Although he was never very prominent in the party's affairs, he attended its conferences on behalf of the union and served four years as vice president of the Wellington Labour Representation Committee. In 1938 he stood, unsuccessfully, in local body elections on a Labour ticket.
Ken Baxter was an important figure in local and national trade union politics. He served on the executive of the Wellington Trades Council and was active in the management of the Wellington Trades Hall, where his union's office was located. He attended the foundation conference of the New Zealand Federation of Labour (FOL) in 1937, and unsuccessfully sought election to its national council on several occasions. In 1944, after the resignation of Fred Cornwell, Baxter was elected national secretary of the FOL, a full-time paid position which he held until his retirement in 1969. He resigned his offices with the printing trades union, and was made a life member to mark his contribution over the previous decade.
As secretary Baxter was responsible for the day-to-day running of the FOL. This involved a heavy load of administration, which he performed methodically and efficiently. In 1967 he noted that he had written all of the federation's annual reports for the last 24 years except the anti-communist sections, which were written by Fintan Patrick Walsh. Baxter and Walsh had a close working relationship dating back to 1936–37 when Walsh had helped the printers win the 40-hour week. Baxter spent two periods as editor of the New Zealand Federation of Labour Bulletin (1949–52 and 1963–64), and represented the FOL on the boards of the Standard and Southern Cross newspapers, the Immigration Advisory Council, the Workers' Compensation Board, the Industrial Advisory Council and other bodies. He was also responsible for the adoption of the federation's distinctive hammer symbol.
Baxter's political development was complex and in some ways contradictory. While he spent much of the 1940s and 1950s attacking communism he still considered himself a Marxist. He retained an unwavering commitment to the class struggle, a critical view of the arbitration system and a certain suspicion of Labour politicians. This was starkly demonstrated in 1963 when party leader Arnold Nordmeyer suggested to the FOL conference that the class struggle was irrelevant. Baxter replied with a vehement defence of the traditional position. By the 1960s, however, Baxter thought socialism should be achieved through the ballot box rather than violent revolution, arguing that it was preferable to 'count heads not crack them'. Mindful of the necessity for immediate and realistic material gains for workers, he sought not 'mansions in the sky but houses for workers here on earth'.
When Ken Baxter announced his intention to retire in 1969 it came as a surprise to his colleagues in the FOL. His decision was prompted by personal reasons, including his deteriorating hearing and Neah's continuing poor health. This, along with the burden of family responsibilities, had long restricted her formal involvement in politics. In addition, both Ken and Neah were unsettled when they had to move out of their longtime residence in Coombe Street, Mount Cook, to make way for the new Wellington Polytechnic. Neah Baxter died in Wellington on 24 December 1973.
Ken Baxter was a small, wiry man, always physically active. He never owned a motorcar and preferred to walk to work. In his youth he had played rugby, and later in life he spent his limited leisure time fishing and shooting; in retirement he was a passionate gardener and lawn bowler. He was a greatly respected figure in the labour movement and was made a life member of several unions. Retirement, however, did not sit well with a man who had worked hard all his life. He soon took part-time work as a printer and often acted as an adviser to unions. Baxter died in Wellington on 13 June 1975, survived by his three children. He was cremated and his ashes were returned to Naseby.