U.S. presidential candidates frequently make campaign promises they can’t deliver once in power.

But usually they wait until they take office to publicly change their minds. President-elect Donald Trump, within days of winning the election, has already backpedaled on some core domestic positions that got him elected to a degree that may be unprecedented, according to historians.

“I’ve never seen anything quite like this so quickly backtracking on the signature issues on which he ran,” said Allan Lichtman, the presidential historian at American University who was virtually alone in forecasting Trump’s Nov. 8 victory over Hillary Clinton.

“Nothing comes to mind of a president-elect beginning to issue a series of, if not retractions, modifications, so rapidly,” said Bruce Buchanan, a University of Texas historian who’s written several books on the presidency.

Trump’s policy shifts offer early signs as to how he may govern as the most unpredictable candidate in recent history to arrive at 1600 Pennsylvania Avenue.

The real estate billionaire ran a campaign largely on personality — casting himself as the populist hero of a forgotten working class, even breaking with party orthodoxy in pledging to reject Social Security cuts that his party insists are necessary to preserve the program. Now Trump will lean heavily on the same establishment Republican leadership he disparaged during the campaign to craft his domestic agenda. “I wouldn’t be surprised to see lots of rewriting of Trump proposals with congressional input,” Buchanan said.

Among the vows being reevaluated or scrapped: appointing a special prosecutor to investigate Hillary Clinton; placing a ban on non-citizen Muslims; abolishing the Affordable Care Act; and bringing back U.S. coal-industry jobs. And while Trump vowed to protect Social Security, he may be OK with restructuring Medicare, which could lead to cuts to the program.

Trump softened some positions during the campaign, for instance circumscribing his Muslim ban to certain nations. But on others including abolishing Obamacare, he was unequivocal. Trump never talked about potentially amending the law — until after the election.

During the campaign, many of Trump’s staff and senior advisers were “not aware of how to frame legislation and what’s possible and what’s not,” Buchanan said. “We’re still in the blush of the honeymoon stage and will be for a while. But a lot of the stuff he talked about isn’t going to happen.”

Protecting the safety net

Congressional Republicans led by House Speaker Paul Ryan, R-Wis., have long wanted to rewrite social safety net programs resulting in cuts to programs like Social Security and Medicare -- which account for at least half of the federal budget -- that Trump’s working-class voters disproportionately rely on. On Tuesday, Ryan celebrated a “unified” party. And while in the past Trump vowed not to cut Medicare or Medicaid, according to his new transition website, he wants to “modernize Medicare,” borrowing the language congressional Republicans have long used.

“One of the biggest misnomers in this election is to call Donald Trump a populist,” Lichtman said..

It’s also difficult to know precisely what the Trump administration will do since, unlike presidential teams before them, they’ve held no news conferences since the election to clarify their plans. Further, items on their website appear to have been both updated and deleted over the past several days. Among items he campaigned on missing from his website is his vow to allow Americans to import prescription drugs from other countries where they’re sold at lower prices.

Investigations

Trump had vowed to appoint a special prosecutor “immediately, immediately, immediately,” to investigate Hillary Clinton, even quipping during a debate that if he were elected Clinton would be “in jail.”

As a result, the Democratic nominee was regularly taunted by protesters wielding “lock her up” signs who believed she would ultimately end up in jail — though she was cleared by the FBI of any criminal charges related to her private email server.

In his first television interview after the election, Trump seemed to reject the idea of a special prosecutor and sounded more like the Trump of five years ago, when he praised the Clintons as a great family. "I don't want to hurt them, I don't want to hurt them," Trump told CBS News. "They’re, they’re good people. I don't want to hurt them,” Trump told CBS.

Immigration

Trump has refused to answer questions about his proposed Muslim ban — it is not listed on his website under the immigration reform tab — and it’s unclear how his deportation policy would differ from current law. In his CBS interview, Trump also said he wants to immediately deport 2 to 3 million undocumented immigrants who are “gang members, drug dealers” or have other criminal convictions.

The Migration Policy Institute estimates there are roughly 11 million immigrants in the United States illegally and 820,000 of them have criminal records.

Trump's policy is in line with orders Obama gave when he first took office to prioritize deportation of immigrants with criminal convictions, which led to a record number of deportations. More recently, Obama’s prioritized deporting those guilty of the most serious crimes.

Repealing Obamacare

On the stump, Trump made repealing and replacing the “disaster” of Obamacare a key talking point, warning it will “destroy American health care forever.”

As president-elect, Trump told the Wall Street Journal he was reconsidering his stance after a Thursday meeting with Obama, who urged him to protect parts of the law.

Trump said he would like to keep the provision forbidding discrimination based on pre-existing conditions and to allow young Americans to remain on their parents' health care plans. "Either Obamacare will be amended, or repealed and replaced," he told the Wall Street Journal, acknowledging Obama had encouraged him to reconsider. "I told him I will look at his suggestions, and out of respect, I will do that."

Coal jobs

Trump promised repeatedly during his campaign to bring back coal jobs, calling himself the “last shot for the miners” and vowing to undo Obama-era clean energy regulations. It was a winning and, in many ways, emotional argument for miners who cited Clinton’s comments that she would put the coal industry out of business. She later apologized and said she would try to move those depressed areas toward a new era of green energy and other jobs.

Now, Republicans are saying it’s not the government’s role to bring back the jobs as companies invest in other forms of energy, including natural gas and wind energy, irrespective of any regulatory measures. Senate Majority Leader Mitch McConnell, R-Ky., recently said it’s “hard to tell” if the jobs will return because “it’s a private-sector activity.”

Democrats have been quick to pounce on the reversals. Felicia Wong, president of Roosevelt Institute held a Tuesday conference call with reporters: “We are seeing the real Donald Trump and it is not what people voted for,” she said.