(S (S (ADVP (RB However)) (COMMA ,) (S (BASENP (DT a) (JJ recent) (NNP Pew) (NNP Research) (NNP Center) (NN study)) (VP (VBZ suggests) (SBAR (IN that) (S (BASENP (DT the) (NN issue)) (VP (MD will) (VP (VP (VB remain) (PP (IN at) (NP (BASENP (DT the) (NN forefront)) (PP (IN of) (BASENP (DT the) (JJ American) (JJ political) (NN agenda)))))) (PP (IN for) (NP (BASENP (JJ many) (NNS years)) (SBAR (S (VP (TO to) (VP (VB come)))))))))))))) (PERIOD .))