Just so you know... that Lincoln "quote" is false.
Lincoln did write once about exiled anti-war Democrat Clement Vallandigham:
"Long experience has shown that armies can not be maintained unless desertion shall be punished by the severe penalty of death. The case requires, and the law and the Constitution, sanction this punishment-- Must I shoot a simple-minded soldier boy who deserts, while I must not touch a hair of a wiley agitator who induces him to desert?"
Basically suggesting the same thing. But there never was any execution. Lincoln commuted Vallandigham's prison sentence and exiled him. Vallandigham returned to America years later and went back to work for the Democratic party.