Sen. Jeff Flake (R-Ariz.) says the Republican president in the White House is not displaying the conservatism his party should be embracing. In his new book, "Conscience of a Conservative," Flake says populism and protectionism are as threatening to the GOP now as the New Deal was in 1960. (Dalton Bennett,Kate Woodsome/The Washington Post)

Sen. Jeff Flake has been getting a lot of attention for his attacks on President Trump, Trump the candidate — and the senator’s own Republican Party for abetting both in recent months.

His argument is a wide-ranging conservative manifesto against Trumpism.

Against the president’s “seeming affection for strongmen and authoritarians,” as Flake wrote for Politico this week.

And against the White House’s demonization of Muslims and Mexicans, Flake (Ariz.) writes in his new book, “Conscience of a Conservative.”

And “a far-right press that too often deals in unreality,” and right-wing voters’ celebration of anger and a Republican Party that “abandoned its core principles” in the course of a single year in 2016.

And on and on goes this list of conservative betrayals in the past two years.

But Sunday, as he promoted his book on NBC’s “Meet the Press,” Flake took his assault on Trumpism back years further — all the way to the pre-dawn of Trump’s political rise, to “when the birtherism thing was going on,” as Flake put it to host Chuck Todd.

“Some people did stand up, but not enough,” the senator said. “That was particularly ugly.”

“Did you do enough?” Todd asked.

Flake smiled. “On that, I think I did.”

Flake was a congressman in 2011, when Trump flirted with a presidential run against President Barack Obama.

The current president did so “spouting all sorts of Four-Pinocchio innuendo that had long ago been debunked,” as The Washington Post wrote at the time.

Trump wrote a letter to the editor in the New York Times, for example, advancing a host of bogus evidence against Obama’s birth in the United States and, thus, his legitimacy to occupy the White House.

“His grandmother from Kenya stated, on tape, that he was born in Kenya and she was there to watch the birth,” Trump wrote, which was a false assertion.

“He has not been able to produce a ‘birth certificate.'” Also false.

“If he was not born in the United States,” Trump concluded, reporters “would have uncovered the greatest ‘scam’ in the history of our country.”

A few weeks later, Trump decided not to run in 2012. But on his ever more popular Twitter account, he continued to stoke birtherism throughout the election and Obama’s second term …

… and right into the 2016 race, when, of course, he did run for president.

“He was still winking and nodding at the issue on television as late as December 2015,” Jonathan Capehart noted in The Washington Post.

“He has said he’s an unapologetic birther,” Flake told the Arizona Daily Star in June 2016. “I think he knows a lot of Republicans believe it and he’s willing to pander to them.”

But the senator issued a caveat: “I don’t know if he thinks these things.”

Flake was by then halfway through his first term as a U.S. senator — in a state Trump would win comfortably in a few months.

In a short essay that summer, Flake lumped birtherism in with another black mark on Trump’s campaign: his crowds’ habit of chanting “Lock her up” — a threat to jail Democratic candidate Hillary Clinton.

“Republicans are not going to defeat Hillary Clinton in November by insisting that she belongs in prison any more than we defeated Barack Obama by pretending that he was born in Kenya,” Flake wrote on Medium.

“These jokes and bromides may play well in rare venues and limited circles, but they cheapen the very real arguments that need to be made to the broader public against a Hillary Clinton presidency.”

He kept up his attacks on Trump that summer, although birtherism was hardly at the top of the list of alleged sins.

“I’m the other senator from Arizona — the one who didn’t get captured,” he told the candidate when they met in July, according to a report in The Post.

Flake was referring Sen. John McCain (R-Ariz.) — and to Trump’s earlier disparagement of the Vietnam War veteran’s service.

“I want to talk to you about statements like that,” he told his party’s presumptive presidential nominee.

Flake offered his support if Trump would change his tone, but Trump never did.

On the contrary, Trump added to his repertoire of polemics by attacking Flake as weak.

So Flake continued to condemn Trump, right up until Election Day, and then made another attempt at reconciliation:

Trump had, at least, renounced birtherism before he won the election — although, unlike Flake, he did so on crow-free diet.

When Trump finally admitted that fall that “Barack Obama was born in the United States, period,” he immediately advanced another bogus claim, blaming the birther conspiracy on Clinton and deeming himself a dispassionate investigator who merely revealed the truth.

Whatever grace period Flake extended to Trump in November appeared to have long since ended as the senator promoted his new book.

And Trump, for his part, has reportedly offered $10 million of his own money to help defeat Flake in the 2018 Republican primaries.

It’s hard to see how taking on birthers helps Flake keep his seat. As of last August — years after Obama’s birth certificate was made public — nearly three-quarters of Republican voters still doubted his U.S. citizenship, according to an NBC News poll.

But Flake’s comment on “Meet the Press” this weekend wasn’t a one-off. He takes swipes at birthers in his book, too:

“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,” he writes in an excerpt published by Politico.

Still, the “Meet the Press” host sounded skeptical that Flake’s condemnations of Trumpism always matched up with his comportment in the Senate.

“You vote with the president 93.5 percent of the time,” Todd said.

Flake countered that he stood up to Trump when it mattered and that most of those votes anyway were just confirmations.

“All we’re really doing is approving the president’s Cabinet picks, justices,” he said.

Flake didn’t mention that one of the judges he voted to confirm was John Bush. Years earlier, as NPR noted, Bush had written blog posts about Obama’s ancestry in Kenya, quoting liberally from sites that peddled some of the first birther conspiracy theories.

More reading:

Jeff Flake: What is happening in the White House is not conservatism

The GOP’s ‘tremendous powers of denial’: Breaking down a Republican senator’s case against Trump