He was certainly a murderer. I wonder what basis you have for the opinion he was a coward.
Not all evil men are cowards. The world would be a much safer place if it were.
Sadly, some evil men are brave and competent. They just decide to use their courage and competence in the service of evil.
Perhaps the fact that he shot a man in the back colored his opinion? It sure does mine.
If he really felt so strongly for “The Cuase’’ he could have fought as a soldier. hell, with his connections he could have been an officer. And rather than confront Lincoln face to face he snuck up on him from behind, waited until the biggest laugh-line in the play and then fired. That’s what I base it on.