What document has every president of the United States used to govern by since Lincoln overthrew the Construction.
Answer: the new, synthetic constitution.
The rock-ribbed Lincolnite Garry Wills in his biography of the rail-, side-, and nation-splitter explained how it went down at the address at Gettysburg.
Lincoln, he recounts, “performed one of the most daring acts of open-air sleight-of-hand ever witnessed by the unsuspecting. Everyone in that vast throng of thousands was having his or her intellectual pocket picked. The crowd departed with a new thing in its ideological luggage, that new constitution Lincoln had substituted for the one they brought there with them. They walked off, from those curving graves on the hillside, under a changed sky, into a different America. Lincoln had revolutionized the Revolution, giving people a new past to live with that would change their future indefinitely.”