A synonym for seldom is rarely.
A synonym for threadbare is worn.
A synonym for constable is detective.
A synonym for illiterate is ignorant.
He is using metaphors heavily in the following paragraphs.
"The energy, the faith, the devotion which we bring to this endeavor will
light our country and all who serve it—and the glow from that fire can
truly light the world." This illustrates his point that they as a nation have a bright future, and their attitudes are empowering, lighting a fire within.
That is a true statement.
