Party CAUCUS: The word and its history.
My summary: despite the greco-latinate spelling and first recorded use in the diaries of one John Adams, ain’t nobody whut knows whar it come from, ‘ceptin that it’s 100% Amurrkin, and thar’s them what say it’s a word we ‘uns come to borry fum the Algonkians er other percursory native types hereabouts.
Among that them, it should be noted, is the linked article’s author, someone better qualified to judge the evidence than I, I’ll warrant.