Kammala wannan magana: A shekara ta 1855, Brainerd yana ɗaya daga cikin waɗanda suka kafa sabuwar jam'iyyar Republican Party sa'ad da aka kafa ta a matsayin babbar ƙungiyar siyasa mai adawa da bautar. Ya yi aiki a matsayin shugaban farko na Jam'iyyar Republican ta Vermont, kuma yana daya daga cikin 'yan shugabannin jihar da suka ba da kira ga jam'iyyar ta farko
taron kasa a shekara ta 1856. Brainerd wakili ne, kuma ya kira taron zuwa tsari a matsayin shugabanta na wucin gadi.