People who insist on precedent and Presidential dignity

[David Lockmiller]

Lincoln's unprecedented public letter caused a sensation. A Washington correspondent for the New York Times reported that people "who insist on precedent, and Presidential dignity, are horrified at this novel idea of Mr. Lincoln's, but there is unanimous admiration of the skill and force with which he has defined his policy."

To what policy of the President Abraham Lincoln administration was the New York Times correspondent making reference?

No Googling please.