(S (S (NP (NP (BASENP (NNP Obama) (POS 's)) (NN emergence)) (PP (IN as) (BASENP (DT a) (JJ potential) (NN contender)))) (VP (VBZ has) (VP (VBN led) (S (BASENP (DT some) (NNS observers)) (VP (TO to) (VP (VB suspect) (SBAR (S (BASENP (NNP Clinton)) (VP (VBZ has) (VP (VP (VB stepped) (PRT (RP up))) (NP (BASENP (PRPD her) (NN timetable)) (PP (IN for) (S (VP (VBG making) (NP (BASENP (DT a) (NN decision)) (PP (IN about) (BASENP (DT a) (NN run)))))))))))))))))) (PERIOD .))