Lincoln's Gettysburg Address: the SECRET Meaning

(Nov.19 is the anniversary of Lincoln delivering the Gettysburg Address on Nov.19, 1863.)
Let me sum up the Gettysburg Address: the Union armies had to win the Civil War, or else democracy ("government of..by.. and for the people") might "perish from the earth."
Lincoln had to be thinking of interracial democracy "perishing from the earth,"
because whites-only democracy was well established in both the north and the south,
and was in no danger whatsoever of "perishing" regardless of which side won the war.

If this is true (that a future interracial democracy is what Lincoln had in mind), why didn't Lincoln say so outright??
Well he did manage to quote this line from the Declaration of Independence:
"all men are created equal."
And the implication of those words is that whites-only "democracy" should eventually expand into interracial democracy.
By including those famous words,
 Lincoln revealed what was in his heart.
Yes, the North had to win, otherwise the prospect or possibility of interracial democracy would truly "perish from the earth."