“This is my last term,” McCain, 81, writes in his upcoming book "The Restless Wave." An excerpt of the book was posted Monday on Apple News.
“If I hadn’t admitted that to myself before this summer, a stage 4 cancer diagnosis acts as ungentle persuasion,” McCain continues.
The senator was re-elected in 2016. Members of the Senate serve six-year terms.
McCain has spent the last several months in his home state of Arizona recuperating from the side effects of brain cancer treatment. He was admitted to the hospital earlier in the month after undergoing surgery to treat an intestinal infection related to diverticulitis. His office confirmed the senator is now in stable condition and is resting at home.
According to the excerpt, McCain says he feels liberated to speak his mind following his cancer diagnosis.
“I’m freer than colleagues who will face the voters again. I can speak my mind without fearing the consequences much. And I can vote my conscience without worry. I don’t think I’m free to disregard my constituents’ wishes, far from it. I don’t feel excused from keeping pledges I made. Nor do I wish to harm my party’s prospects. But I do feel a pressing responsibility to give Americans my best judgment.”
McCain also takes sharp jabs at President Donald Trump.
“He has declined to distinguish the actions of our government from the crimes of despotic ones,” McCain writes. “The appearance of toughness, or a reality show facsimile of toughness, seems to matter more than any of our values.”
He also describes his dismay at the current political environment.
“I suspect it’s never been in abundant supply in most human enterprises,” McCain writes. “And I don’t mean modesty. Any politician worth a damn can fake modesty. Humility is the self-knowledge that you possess as much inherent dignity as anyone else, and not one bit more. Among its other virtues, humility makes for more productive politics.”
McCain says he that "before I leave I'd like to see our politics begin to return to the purposes and practices that distinguish our history from the history of other nations.”
"I would like to see us recover our sense that we are more alike than different," he added.
"'The world is a fine place and worth the fighting for and I hate very much to leave it,' spoke my hero, Robert Jordan, in For Whom the Bell Tolls," McCain wrote in his book. "And I do, too. I hate to leave it. But I don't have a complaint. Not one. It's been quite a ride. I've known great passions, seen amazing wonders, fought in a war, and helped make a peace. I made a small place for myself in the story of America and the history of my times."
His memoir is expected to be released on May 22.