Sentence:  On the positive side , recent Federal action has largely undermined the legal sanction so long enjoyed by the segregationist position ; anti-discriminatory statutes in housing have now been adopted by thirteen states and , while specific provisions have varied , the tendency <WSD>is</WSD> clearly toward expanding coverage . 
Meaning of the word marked with <WSD> tags:  have the quality of being; (copula, used with an adjective or a predicate noun)