Washington (CNN) If you want to understand the profound impact Donald Trump's candidacy and presidency have had on the Republican Party, you need look no further than Tuesday's announcement that the DACA program will be rescinded.

"We are a people of compassion and we are a people of law," said Attorney General Jeff Sessions in announcing the decision, which could jeopardize the immigration status of nearly 800,000 people who were brought to America illegally before the age of 16. "But there is nothing compassionate about the failure to enforce immigration laws."

That view -- that the rule of law trumps (ahem) all else when it comes to the nation's immigration problems -- is a massive reversal from views espoused by George W. Bush in his two terms as president and in the autopsy document produced by the Republican National Committee in the wake of the party's disastrous 2012 presidential election loss.

"Family values don't stop at the Rio Grande and a hungry mother is going to try to feed her child," Bush famously said.

That quote was cited in the RNC's post-2012 "Growth and Opportunity Project" report -- in which a large group of party leaders tried to diagnose what had gone wrong for the party and how to fix it heading into the 2016 race.

These lines from the GOP autopsy , which also advocated that Republicans find a way to support comprehensive immigration reform, are particularly striking:

"If Hispanic Americans perceive that a GOP nominee or candidate does not want them in the United States (i.e. self-deportation), they will not pay attention to our next sentence. It does not matter what we say about education, jobs or the economy; if Hispanics think we do not want them here, they will close their ears to our policies."

The RNC report, which was unveiled by none other than Reince Priebus, who back then was the RNC chairman but went on to be Trump's first White House chief of staff before he was ousted in July, warned that a failure to change its attitude toward Hispanics would likely result in "our party's appeal will continue to shrink to its core constituencies only."

Less than four years after the release of that report, Donald Trump won the Republican presidential primary on the strength of his hardline views on illegal immigration: end DACA, build a wall, Mexicans are rapists and criminals, etc. -- and, in so doing, steered the party on a radically different course.

The signs that a Trumpian approach to immigration would work were evident long before than RNC autopsy report.

John McCain had watched his front-running campaign for the 2008 nomination nearly collapse due to his support for comprehensive immigration reform.

During the 2012 primary season, Texas Gov. Rick Perry had been lambasted for saying this in a debate : "If you say that we should not educate children who have come into our state for no other reason than they've been brought there by no fault of their own, I don't think you have a heart."

Mitt Romney, the party's 2012 nominee, was cowed by the reaction to Perry's "heart" comments. Fearing an insurrection from his ideological right, Romney adopted the incoherent policy of "self-deportation" -- undocumented immigrants would simply choose to leave the country.

The GOP autopsy report was supposed to put an end to all of that. It was seen -- at the time -- as a sort of seminal document, a chapter-closing on the struggles of high-profile Republicans to find a safe space to occupy on immigration reform. If we keep doing what we have been doing, we will not only lose, the autopsy argued, we will be something fundamentally different as a party than what we have been up to this point.

Then Donald Trump started running for president. His promises to build a wall were just what many conservative activists had been longing to hear. They flocked to his rallies and his candidacy -- energized by the idea that, finally, a candidate who truly stood with them on the perils of illegal immigration had emerged.

All of the calls from the Jeb Bushes and Marco Rubios (and the Rick Perrys!, who is now Trump's secretary of energy) of the world about the potential political danger for their party in nominating someone like Trump, who famously and wrongly generalized that Mexicans coming across the border are mostly criminals and rapists, went unheeded. Anger and fear are two very powerful emotions and all of the demographic data in the world couldn't sway voters.

Trump's victory over Hillary Clinton -- in which he carried more of the Hispanic vote than Romney had four years earlier -- was seen as a validation for these Republicans.

But, if anything, it was a delaying of the inevitable; Trump's razor-thin margins in three predominately white Rust Belt states (Michigan, Wisconsin and Pennsylvania) handed him the presidency but didn't change this basic fact: The GOP cannot remain a majority party at the presidential level for much longer if they can't win more than three in 10 Hispanic voters.

How Trump has governed since assuming the presidency is as problematic as how he ran for the office. The decision on DACA coupled with the pardon of controversial former Maricopa County Sheriff Joe Arpaio sends a very clear signal to Hispanic Americans -- and it's the opposite signal that the GOP autopsy recommended.

Hispanics are listening. In a Washington Post/ABC News poll conducted in mid-July -- before the Arpaio pardon and the DACA decision -- just one in five Latinos approved of the job Trump was doing while 75% disapproved.

Sessions, in defending the decision to rescind DACA, noted this: "To have a lawful system of immigration that serves the national interest, we cannot admit everyone who would like to come here. That is an open border policy and the American people have rightly rejected it."

But, in drawing the line of admission at children brought to the US without their consent or knowledge, the Republican party is re-inventing itself as something radically different than the party of Bush, McCain and even Romney.

"Instead of driving around in circles on an ideological cul-de-sac, we need a party whose brand of conservatism invites and inspires new people to visit us," the authors of the Republican autopsy wrote. "Our standard should not be universal purity; it should be a more welcoming conservatism."

That party simply doesn't exist any longer.