must be a serious contender for the title 
(ROOT (S (VP (MD must) (VP (VB be) (NP (NP (DT a) (JJ serious) (NN contender)) (PP (IN for) (NP (DT the) (NN title))))))))
(ROOT (S (VP (MD ) (VP (VB ) (NP (NP (DT ) (JJ ) (NN )) (PP (IN ) (NP (DT ) (NN ))))))))