Sentence:  What Sam Rayburn 's life proves to us all is the magnificent lesson in political science that one can devotedly and with absolute dedication represent the seemingly provincial interests of one 's own community , one 's own district , one 's own State , and by that help himself <WSD>represent</WSD> even better the sweep and scope of the problems of this the greatest nation of all time . 
Meaning of the word marked with <WSD> tags:  be a delegate or spokesperson for; represent somebody's interest or be a proxy or substitute for, as of politicians and office holders representing their constituents, or of a tenant representing other tenants in a housing dispute