"I cannot sustain hate for longer than a couple of years"

In this quote, Mercedes McCambridge is expressing her failure to hold onto feelings of hate for a prolonged amount of time. She acknowledges that while she might experience hate towards someone or something, it is not a long lasting feeling for her. This could suggest that McCambridge is a forgiving and understanding person, who is able to let go of unfavorable emotions and move on. It likewise highlights the idea that hate is not a sustainable emotion and eventually fades away. McCambridge's words work as a pointer that holding onto hate only triggers damage which it is very important to let go and move forward.