Yes, I think that Tom Hayden will be mostly remembered for his radical years, even though he seemed to move past that and spend the 2nd half of his life in a different way. Unfortunately, your past follows you, and there is probably nothing he could've done to escape his past.
While any individual, famous or not, can be remembered for acts of kindness and good, our tendency in society is to remember more profoundly the bad or controversial actions of an individual. I think this will be the case for Tom Hayden. His radical life will be remembered more than any normal acts he may have had.
His work as a vietnam activist is what made him famous. Outside of this most people have no idea what his accomplishements were. He is sure to be rembered for the work he did during those years and not anything the did between that time and the time he died.
Tom Hayden died at the age of 76. I do not believe he will be remembered primarily for his radical years. Tom hayden was a political activist, but I had never heard of him before. In fact I had to Google him. Unfortunately, I do not believe he will be remembered at all.