Grand Rapids, Mich. • It is difficult to discourage and impossible to manage Justin Amash because he, unusual among politicians, does not want much and wants nothing inordinately. He would like to win a sixth term as congressman from this culturally distinctive slice of the Midwest. He does not, however, want it enough to remain in today’s Republican Party, which he has left because that neighborhood has become blighted. Amash, 39, a founding member of the House Freedom Caucus, also has left that once-admirable faction because he does not define freedom as it now does, as devotion to the 45th president.