‘Twas a slow and cruel vengeance, and showed he had neither God nor conscience before his eyes.
This is in reference to the slow and calculated nature in which the President enacted his plan. By first saving face, sending away the servant who informed him and then Nicholas, and then poisoning his wife with a salad. It could be said that there is no God before his eyes because in the Bible's book of Exodus, Chapter 21, Verses 14 it states "But if anyone schemes and kills someone deliberately, that person is to be taken from my altar and put to death."
New International Version. (2011). The Holy Bible: New International Version. Zondervan.