When former President Donald Trump shocked the nation by winning the 2016 presidential election, his predecessor—then-President Barack Obama—didn't shout that the election was rigged, didn't file frivolous lawsuits, and didn't set the stage for a deadly failed insurrection of the United States Capitol.

Instead, he told the nation to accept the results and hope for the country's success under Trump.

Obama addressed the nation shortly after Trump's win, saying:

"[W]e are now all rooting for [Trump's] success in uniting and leading the country. The peaceful transition of power is one of the hallmarks of our democracy. And over the next few months, we are going to show that to the world."

It wouldn't be until the 2020 presidential campaign started heating up—three years later—that Obama would begin openly criticizing Trump's record while campaigning for then-Democratic nominee Joe Biden.

But even then, Obama wasn't speaking freely about his real opinion of Trump, as a new book reveals.

Battle for the Soul: Inside the Democrats' Campaigns to Defeat Donald Trump by Edward-Isaac Dovere will hit shelves next week, but a preview reveals that Obama was much less inhibited regarding his feelings on Trump in private.

Dovere writes in an excerpt:

"[Obama said] More often: 'I didn't think it would be this bad.' Sometimes: 'I didn't think we'd have a racist, sexist pig.' Depending on the outrage of the day … a passing 'that f**iing lunatic' with a shake of his head."

When Trump was reportedly speaking to world leaders like Vladimir Putin without aides listening in, Dover reports that Obama remarked:

"That corrupt motherf***er."

Obama may have been restrained while Trump was President, but people found his remarks relatable all the same.

Some thought even those remarks didn't go far enough.

Trump has yet to respond to Obama's remarks.