(S (S (PP (IN In) (BASENP (NN one) (NN case))) (COMMA ,) (S (BASENP (NN one) (NN lawmaker)) (VP (VP (VBD switched) (BASENP (NNS parties))) (COMMA ,) (S (VP (TO to) (VP (VB maintain) (BASENP (NN office)))))))) (PERIOD .))