that should shame americans , regardless of whether or not ultimate blame 
(ROOT (S (NP (DT that)) (VP (MD should) (VP (VB shame) (NP (NNPS americans)) (, ,) (ADVP (RB regardless) (PP (IN of) (SBAR (IN whether) (CC or) (RB not) (S (NP (JJ ultimate)) (VP (NN blame))))))))))
(ROOT (S (NP (DT )) (VP (MD ) (VP (VB ) (NP (NNPS )) (, ) (ADVP (RB ) (PP (IN ) (SBAR (IN ) (CC ) (RB ) (S (NP (JJ )) (VP (NN ))))))))))