How can you not be moved by reading Lincoln?

There are numerous touching stories of Lincoln’s reading Shakespeare in Carl Sandburg’s Lincoln; here is another one (Carl Sandburg's Lincoln, Book II, p 314).

Lincoln's son, Willie

“On a Fortress Monroe trip, not long after the boy Willie had died [Willie died about one year after Lincolns moved into White House], he took up a volume of Shakespeare and read aloud to General Wool's aide several passages from Hamlet and Macbeth; then after reading from the third act of King John, he closed the book and repeated from memory the lament of Constance for her boy— ”
Constance:
And father cardinal, I have heard you say

That we shall see and know our friends in heaven.

If that be true, I shall see my boy again.

                   King John Act 3 Scene 4

Lincoln mourned the death of her son just like Constance did her son’s (Arthur); Shakespeare made Constance a character best known as the mother lamenting the loss of her son,

O Lord! my boy, my Arthur, my fair son!

My life, my joy, my food, my all the world!

My widow-comfort, and my sorrows’ cure!

(Constance’s husband is the second son of Henry II, who had died, thus “My widow-comfort”; King John is the third son.  If you see The Lion in Winter or read T.S. Eliot’s The murder in the cathedral, you should know a bit about Henry II)