He was elected three times as a Progressive Conservative Party member of the Legislative Assembly of Manitoba representing the Portage la Prairie riding from 1933 to 1943.

The Allan Cup was formally recognized as the senior ice hockey championship of Canada while Sexsmith was CAHA president, and eligibility rules were expanded to allow more teams to compete for the title.

He began the efforts to establish a standard set of national ice hockey rules and amateur competitions between the United States and Canada.

He died in office on his 58th birthday, and was credited by the Winnipeg Free Press as a person who tackled contentious issues, and gave sound advice and constructive criticism.

[4] Sexsmith played as a winger on the 1906 Portage la Prairie men's ice hockey team, and was a teammate to Harry Scott.

[5] Sexsmith scored eleven goals in six games played for the Portage la Prairie Cities in the Manitoba Professional Hockey League.

[19] The CAHA requested changes to the expand the eligibility for the Allan Cup, the national championship of Canadian senior hockey.

The Allan Cup was formally recognized as the senior ice hockey championship of Canada with an annual series of national playoffs.

Teams participating in the semifinals and finals would have legitimate expenses reimbursed, with CAHA executives overseeing administration of schedules and finances.

[22] Sexsmith ruled that clubs from the Thunder Bay Amateur Hockey Association would not play in the MAHA due to constant arguments over placement in divisions.

[30] He worked with the local Elks of Canada lodge in Portage la Prairie in 1926, to oversee youth hockey in the city and to encourage boys to play and learn sportsmanship.

[14] Portage la Prairie tax payers approved a by-law to begin construction of a new rink with a financial guarantee of $15,000 from the city.

The new Portage Rink was built using concrete, had seating for 1,900 spectators and standing room for another 700, included a public address system, and cost approximately $21,000 to build.

He felt that the money allocated to send a national team to Europe would be better spent on minor ice hockey in Canada.

[7] Since being president, he had served on the registration committee, and acted as convenor for the intermediate level playoffs and the junior ice hockey B-level division.

[2][3][48] On April 27, 1933, he was named as the Conservative candidate for the Portage la Prairie electoral district to replace Fawcett Taylor who resigned when he became a judge on the Court of Queen's Bench of Manitoba.

[49] Sexsmith submitted a request at the first meeting of the provincial government since prorogation, to call a by-election to fill the vacancy in Portage la Prairie.

[50] In the subsequent campaign, the Winnipeg Free Press reported that political issues were absent in the by-election, which seemed to a popularity contest between Sexsmith, and another local hockey figure in E. A. Gilroy who ran as an independent candidate.

[52] Sexsmith served in the 19th Manitoba Legislature to represent the Portage la Prairie in opposition to the governing Liberal-Progressive coalition led by John Bracken.

[53] Sexsmith made his first speech in the legislature in March 1934, and declared himself a "true Blue Tory" and "a man of decided liberal and progressive views".

He noted that outdated systems could not adequately protect agriculture from floods, and new highway construction left some areas more vulnerable than others, and estimated the problem to cost $6-million.

[55] He sought to expedite negotiations with the Government of Canada for relief payments, and protect Manitoba from interest on infrastructure projects which included improvements to drainage.

[69] When Premier Bracken asked legislature members if they would agree to a nighttime session of parliament on March 27, Sexsmith was opposed to longer hours while the Portage Terriers were in the 1942 Memorial Cup playoffs and felt compelled to support his hometown team.

[2] In March 1942, Sexsmith introduced a bill to allow Portage la Prairie to impose a 2% tax on liquor sales to its permit holders.

He explained that similar to legislation existed in Winnipeg to raise funds, and that Portage la Prairie had not paid interest on its debts in three years and were struggling since relief payments from the province had been reduced.

[79] Sexsmith was the guest of honour at a banquet for him by the citizens of Portage la Prairie in 1923, in recognition of his sporting accomplishments and service as president of the CAHA.

[82][83] In his obituary, the Winnipeg Free Press credited Sexsmith as a person who tackled contentious issues, and gave sound advice and constructive criticism.