Here’s a little more for you:
“You don’t see me running off to Canada,” he said. “I’m not burning my draft card or burning the American flag. You can put me in jail or shoot me but I’m not going in no army to fight against people that don’t even call me the names I’ve been called in my own country.”
http://www.nydailynews.com/sports/muhammad-ali-knew-tribute-late-bill-gallo-article-1.2660767
Doesn’t sound like a guy disavowing his country to me.
That is called sedition and most people who have taken that position in our 200+ year history were executed for it, the Viet Nam Era excepted.