The same year he joined the Mining and Smelter workers Union where he was elected as Secretary for the Trail chapter. Following his involvement with trade unions, Goodwin entered politics running as a candidate for the Socialist Party of Canada in the 1916 British Columbian election representing Trail. Although he did not win, Goodwin carried on with his union activity. The following year he was elected to the executive of the British Columbia Federation of Labour as Vice-President, and as the President of District 6 (Kootenays) of the International Union of Mine, Mill and Smelter Workers. Goodwin commonly spoke out against Canada's involvement in World War I as a conscientious objector. He rejected conscription on the grounds that workers of one country should not be employed to kill workers of another country under the influence of a capitalist conflict. Goodwin is credited with saying, "War is simply part of the process of Capitalism. Big financial interests are playing the game. They'll reap the victory, no matter how the war ends." While Goodwin eventually did sign up for the draft, he was initially exempted from conscription after a medical examination found him unfit for service. Following his exemption, Goodwin called for a strike on November 10, 1917 at the Trail Smelter where he worked in an attempt to establish an eight-hour work day. As the strike continued, Goodwin was recalled for medical examination and as a result, was then ordered to report for duty for overseas, contrary to the decision priorly made. After being reinstated for conscription, Goodwin attempted to appeal his assignment for conscription but was denied multiple times. After being denied, he returned to Cumberland once more to prepare his final appeal. While back on Vancouver Island, Goodwin and other draft evaders fled to the hills of Cumberland in sometime in April or May 1918, hiding out in the mountains around Comox Lake. By breaking into a cabin, Goodwin and the other objectors were able to survive with supplies provided by friends and community members. On July 27, 1918 Dominion Police ventured into the hills surrounding Comox Lake to locate men evading the draft and arrest them for their evasion. On this day, a Dominion Police Officer by the name of Dan Campbell encountered Goodwin in the woods surrounding Comox Lake. Upon his encounter with the activist, Campbell shot Goodwin with a .30-30-calibre lever-action hunting rifle. Campbell claimed that the shot was fired in self-defence after Goodwin raised his own rifle at him after asking him to surrender. It is unknown how the two men actually encountered each other, as there were no other witnesses to the event.