Sen. Jeff Flake (R-Ariz.) speaks at a town hall event in April in Mesa, Arizona. Flake said the Republican Party is “in denial” about President Donald Trump in an excerpt from his new book published by Politico on Monday. 

• Republican Sen. Jeff Flake (Ariz.) believes that his party is “in denial” about President Donald Trump, an excerpt from his new book revealed.

Flake, author of “The Conscience of a Conservative: A Rejection of Destructive Politics and a Return to Principle” — a reference to Arizona GOP Sen. Barry Goldwater’s 1960 book “Conscience of a Conservative” — wrote that the country has entered “one of the more reckless periods of politics in our history,” according to the passage posted by Politico on Monday.

“Who could blame the people who felt abandoned and ignored by the major parties for reaching in despair for a candidate who offered oversimplified answers to infinitely complex questions and managed to entertain them in the process? With hindsight, it is clear that we all but ensured the rise of Donald Trump,” Flake wrote.

He noted that — while liberals have “their own sins” to answer for — conservatives for years “mocked Barack Obama’s failure to deliver on his pledge to change the tone in Washington even as we worked to assist with that failure”:

It was we conservatives who, upon Obama’s election, stated that our No. 1 priority was not advancing a conservative policy agenda but making Obama a one-term president—the corollary to this binary thinking being that his failure would be our success and the fortunes of the citizenry would presumably be sorted out in the meantime. It was we conservatives who were largely silent when the most egregious and sustained attacks on Obama’s legitimacy were leveled by marginal figures who would later be embraced and legitimized by far too many of us. It was we conservatives who rightly and robustly asserted our constitutional prerogatives as a co-equal branch of government when a Democrat was in the White House but who, despite solemn vows to do the same in the event of a Trump presidency, have maintained an unnerving silence as instability has ensued.

“To carry on in the spring of 2017 as if what was happening was anything approaching normalcy required a determined suspension of critical faculties. And tremendous powers of denial,” he added.

Flake said that he was “sympathetic to this impulse to denial, as one doesn’t ever want to believe that the government of the United States has been made dysfunctional at the highest levels, especially by the actions of one’s own party.”

He further argued, “Under our Constitution, there simply are not that many people who are in a position to do something about an executive branch in chaos.”

“As the first branch of government (Article I), the Congress was designed expressly to assert itself at just such moments,” Flake wrote. “It is what we talk about when we talk about ‘checks and balances.’ Too often, we observe the unfolding drama along with the rest of the country, passively, all but saying, ‘Someone should do something!’ without seeming to realize that that someone is us. And so, that unnerving silence in the face of an erratic executive branch is an abdication, and those in positions of leadership bear particular responsibility.”

“So, where should Republicans go from here?” he asked. “First, we shouldn’t hesitate to speak out if the president ‘plays to the base’ in ways that damage the Republican Party’s ability to grow and speak to a larger audience. Second, Republicans need to take the long view when it comes to issues like free trade: Populist and protectionist policies might play well in the short term, but they handicap the country in the long term. Third, Republicans need to stand up for institutions and prerogatives, like the Senate filibuster, that have served us well for more than two centuries.”

The excerpt echoed Flake’s comments on Sunday’s “Face the Nation” that the Republican Party has “lost its way” in the Trump era.

“I felt that, just like Goldwater had felt in his time, 56 years ago, when he wrote the original ‘Conscience of Conservative,’ that the party had lost its way,” Flake said:

And I think, similarly today, the party’s lost its way. We have given into nativism and protectionism. And I think that, if we’re going to be a governing party in the future, and a majority party, we have got to go back to traditional conservatism, limited government, economic freedom, individual responsibility, respect for free trade. Those are the principles that made us who we are.