Republican presidential candidates Jeb Bush, Sen. Marco Rubio (R-Fla.) and Donald Trump participate in a Feb. 6 presidential debate at St. Anselm College in Manchester, N.H. (Joe Raedle/Getty Images)

For more than a year, Donald Trump took the hardest line on immigration — vowing to deport 11 million illegal immigrants en masse and pillorying his GOP primary rivals as favoring “amnesty.”

But 11 weeks before the election, Trump is suddenly sounding a lot like the opponents he repeatedly ridiculed.

The nominee and his campaign aides are now talking openly about requiring illegal immigrants to pay back taxes and potentially allowing those without criminal records to stay in the country — lines that Sen. Marco Rubio of Florida repeatedly used in the GOP presidential primary. Trump also says that any softening of his position won’t include a path to citizenship — consistent with the way former Florida governor Jeb Bush described how he would provide legal status for undocumented immigrants.

The shift, if it sticks, marks a dramatic turnabout for a nominee who repeatedly attacked Bush, Rubio, Sen. Ted Cruz of Texas and other primary rivals as weak and spineless on immigration, and who repeatedly vowed that he would never waver in his push to deport everyone in the United States who is here illegally.

It was unclear Thursday evening if it would. In an interview with CNN, Trump said “there is no path to legalization unless they leave the country and come back,” apparently returning to at least some version of his original position. Trump’s campaign did not immediately respond to a request for more clarity on his views.

Republican presidential nominee Donald Trump has promised to build a wall along the U.S.-Mexico border if he wins the election. Here's what people living along the border have to say about that wall. (Zoeann Murphy,Samuel Granados,Kevin Schaul,Monica Akhtar/The Washington Post)

In a Thursday radio interview with WABC in New York, Bush said Trump’s views seem to be constantly changing, making it difficult to read where he stands. But he said Trump seems to have turned his back on the positions that have defined his candidacy.

“Sounds like a typical politician, by the way, where you get in front of one crowd and say one thing, and then say something else to another crowd that may want to hear a different view,” said Bush, who has refused to endorse Trump. “All the things that Donald Trump railed against, he seems to be morphing into. It’s kind of disturbing.”

When pressed on the similarities between his position and Trump’s new stance, Bush said with a laugh: “Well, I’m sure I influenced his position.”

Republican advocates of immigration reform came out of the woodwork Thursday to draw attention to Trump’s changing stance. Former House majority leader Eric Cantor, who supported Bush’s campaign, wrote on Twitter: “Pleased to see @realDonaldTrump embrace @JebBush’s immigration plan.” Cantor lost his seat in a 2014 primary upset in part because of his support for immigration reform.

Meanwhile, Democrats are in rare agreement with many Trump defenders in saying that the nominee has not actually flip-flopped. They argue that he is merely trying to paper over ugly remarks that can’t be taken back, such as labeling illegal immigrants from Mexico “rapists” and killers bringing drugs and crime into the United States.

“I don’t think anything has changed,” said Rep. Luis V. Gutiérrez (D-Ill.), a staunch advocate of immigration reform.

Republican presidential candidate Donald Trump has said over and over he would force undocumented immigrants to leave the country as president. Now a meeting with a Hispanic advisory panel and statements from his surrogates are calling into question whether that's still the plan. (Sarah Parnass/The Washington Post)

Following a staff shake-up last week amid worsening poll numbers against Democratic nominee Hillary Clinton, Trump has sought to move to the center — at least rhetorically — in a number of areas, including immigration. Although the nominee has been cagey on the details, Trump’s remarks so far have borne remarkable similarities to the positions that Bush and others held on immigration reform.

For example, Bush wrote in a 2013 book on immigration reform that he supported “a path to earned legal status, not citizenship,” in which undocumented immigrants could obtain “a provisional work permit, where they pay taxes, they pay a fine, they learn English, they work.” He advocated the same in the GOP primaries.

In a town-hall-style interview with Fox News Channel’s Sean Hannity that aired this week, Trump described a similar set of policies. He said there would be “no citizenship” and “no amnesty,” but at the same time he suggested that some otherwise law-abiding illegal immigrants could be allowed to stay if they pay back taxes. “No amnesty, but we work with them,” Trump said.

In an interview on CNN on Thursday morning, Trump’s new campaign manager, Kellyanne Conway, tried to distinguish what Trump is saying from what Rubio, Bush and others advocated.

“Senator Rubio is a particularly different case because he led the Gang of Eight with [Democrats] Chuck Schumer and — and I think Dick Durbin. The Gang of Eight, their plan was amnesty,” she said.

Rubio was part of the Gang of Eight senators who co-sponsored a comprehensive immigration reform bill that included a path to citizenship in 2013. But he backed away from the sweeping approach by the time of his presidential campaign and repeatedly insisted that he did not support “amnesty.”

Rubio also emphasized during his presidential campaign that he would not hesitate to deport illegal immigrants who have committed serious crimes. But he took a more tolerant attitude toward those who did not commit serious crimes.

“If you’re a criminal alien, no, you can’t stay,” he said on NBC’s “Meet The Press” in January, specifying that he meant those who committed felonies. He added: “I don’t think you’re gonna round up and deport 12 million people.”

In that interview, Trump said he would deport illegal immigrants who are “gang members.” But polling the audience, he seemed open to a different approach to those who have not broken laws aside from being in the country without proper documents.

“So now we have the person, 20 years been an upstanding person, the family is great, everyone is great, do we throw them out or do we work with them?” Trump asked the crowd to a mixed reaction.

Trump said Thursday that he will lay out an “exact plan” on immigration in an upcoming speech.

“I will be doing that, I’d say, over the next week or so,” Trump told reporters at Trump Tower in New York. “I look forward to it.”

He insisted that he is “very strong on illegal immigration” and warned not to be fooled by the news media.

“You either have a country or you don’t. We either have borders or we don’t,” Trump said, adding that he would still build a massive wall along the southern border, and make Mexico pay for it, if elected president.

At a Thursday afternoon rally in Manchester, N.H., Trump sought to project strength in his immigration positions, reiterating his commitment to building a wall on the U.S.-Mexico border. But he did not offer any new details on his revised stance.

“We will end illegal immigration, and we will restore the constitutional rule of law,” Trump pledged.

The wavering marks a sharp departure from last year, when Trump said in television interviews on NBC and MSNBC that illegal immigrants “have to go” and he vowed to create a “deportation force.” The tone he has adopted lately no longer includes that language.

As a candidate in the primary, Trump hammered Bush and Rubio for being soft on illegal immigrants.

The issue Bush and Rubio ran into with the GOP base was that many conservatives saw anything short of deporting all illegal immigrants as a form of “amnesty,” which has become one of the most damaging words to be associated with in Republican circles.

Now, Trump risks having the same problem in the final stretch before the general election.

“So what’s Trump going to call his amnesty plan: The Gang of One proposal?” tweeted Mark Krikorian, a staunch opponent of illegal immigration.

Jenna Johnson contributed to this report.