I've found one possible candidate for the line I said reads like a quotation from a speech -

"How far have we come in man's long pilgrimage from darkness toward light? Are we nearing the light--a day of freedom and of peace for all mankind? Or are the shadows of another night closing in upon us?"

From Eisenhower's first inaugural speech, January 1953.

That'd be ten years or more before the earliest date this song could have been put together, at least in its present form. And of course it's a phrase that could crop up in any speech or article.