Sentence:  A year ago today , when the Democrats were fretting and frolicking in Los Angeles and John F. Kennedy <WSD>was</WSD> still only an able and ambitious Senator who yearned for the power and responsibility of the Presidency , Theodore H. White had already compiled masses of notes about the Presidential campaign of 1960 . 
Meaning of the word marked with <WSD> tags:  have the quality of being; (copula, used with an adjective or a predicate noun)