(S (S (BASENP (DT The) (NNP United) (NNPS States) (NNP Senate)) (VP (VBZ has) (VP (VBN defeated) (NP (BASENP (DT a) (VBN proposed) (JJ constitutional) (NN amendment)) (VP (VBG banning) (BASENP (JJ gay) (NN marriage))))))) (PERIOD .))