(S (S (BASENP (NNP Obama)) (VP (VBD signaled) (S (BASENP (PRPD his) (JJ own) (NNS contributors)) (VP (TO to) (VP (VB help) (S (BASENP (NNP Clinton)) (VP (VP (VB pay) (PRT (RP off))) (NP (BASENP (DT the) (NN debt)) (VP (VBN incurred) (PP (IN by) (BASENP (PRPD her) (NN campaign)))))))))))) (PERIOD .))