God bless the copperheads.
You can admire the Confederacy, while still cursing the Copperheads as traitors. Right or wrong, both the Confederacy and the Union had honorable men supporting them. But just because scoundrels side with you does not mean they are, or should be, your friends.
Benedict Arnold was accepted by the British, and they even rewarded him, modestly, for his treason. But they never embraced him, nor saw him as an honorable man thereafter.
Clement Vallandigham then was as Harry Reid is today. Both villains destined for oblivion.