Powell believed the very same thing - or so he told Gillette; that he was "acting as a Confederate soldier; that he was told he would be a hero to the southern people. He also thought that it would bring peace to the south."
I attribute such naivety to his youth and lack of sophistication. Booth was more worldly and should have known better -
"The Past is a foreign country...they do things differently there" - L. P. Hartley