As noted by Frank Bruni @ NYTimes.com, May 5 "John McCain Battles Donald Trump With His Dying Breaths":

[....] McCain has waged it in public remarks since Trump’s election, including a speech in Philadelphia last October, when he pushed back against the “half-baked, spurious nationalism” that was gripping too many Americans and lamented the abdication of America’s moral leadership in the world.

He wages it in a forthcoming book, “The Restless Wave,” an advance excerpt of which includes his complaint that Trump fails “to distinguish the actions of our government from the crimes of despotic ones” and that he prioritizes “a reality-show facsimile of toughness” over “any of our values.”

[....] 

Trump invites pity for all the slights he suffers plus plenty that he only imagines, and he readily boasts about achievements actual and hallucinated. “I don’t have a complaint,” McCain says in his book, which was written with Mark Salter and will be released on May 22. He’s grateful, he adds, that he “made a small place for myself in the story of America.” A small place. I sometimes forget, thanks to Trump, what the music of understatement sounds like.

“There is a scarcity of humility in politics these days,” McCain writes. I wonder if he has anyone particular in mind. No, that’s a lie: All of us know precisely which someone he has in mind, the same person in his thoughts when, in Munich in February 2017, he expressed alarm about an “increasing turn away from universal values and toward old ties of blood and race,” about “the hardening resentment we see toward immigrants” and about “the growing inability—and even unwillingness—to separate truth from lies.”

In his new book he calls out Trump by name, saying that the president’s cries of “fake news” are “copied by autocrats who want to discredit and control a free press” and that his lack of empathy for refugees is “appalling.” “The world expects us to be concerned with the condition of humanity,” McCain writes. “We should be proud of that reputation. I’m not sure the president understands that.” [....]

Although I disagree with many of his political views, including his too-keen itch for foreign intervention, that doesn’t prevent me from admiring him enormously. Nor should it, a point that he makes in his book.

“I don’t remember another time in my life when so many Americans considered someone’s partisan affiliation a test of whether that person was entitled to their respect,” he writes, ruefully, adding that while Biden, Ted Kennedy and other Democratic friends of his never voted for the same candidate for president as he did, his friendships with them “made my life richer, and made me a better senator and a better person.”

Such grace is unimaginable from Trump. That’s why it’s so vital that McCain is using his waning time to model it.

Edit to add excerpt from the above, re: other regrets:

....Even more striking is how Mr. McCain expresses his sorrow in the documentary. He calls the decision not to pick Mr. Lieberman “another mistake that I made” in his political career, a self-indictment that includes his involvement in the Keating Five savings and loan scandal and his reluctance to speak out during his 2000 presidential bid about the Confederate battle flag flying above the South Carolina Capitol.

Mr. Lieberman said he didn’t know Mr. McCain felt that regret until he watched the film. “It touched me greatly,” he said.....

The Arizona senator laments return of ‘old fears and animosities’ in new book The Restless Wave and has no regrets about giving Steele dossier to Comey ​according to  John McCain warns that Republicans are on wrong side of immigration debate

by Lauren Gambino @ The Guardian.com, May 9​