Sentence:  Heywood Broun wrote : `` Belle Poitrine <WSD>is</WSD> the most original thinker since Caligula '' , and even F. D. R. had to concede that `` if the rest of this nation showed the foresight and patriotism of Miss Poitrine , America would rapidly resemble ancient Babylon and Nineveh '' . 
Meaning of the word marked with <WSD> tags:  have the quality of being; (copula, used with an adjective or a predicate noun)