Donald Trump’s campaign wavered Sunday on whether he would continue to call for the mass deportation of 11 million illegal immigrants from the United States, the latest in a series of sometimes-clumsy attempts to win over moderate GOP voters without alienating millions who have flocked to his hard-line views.

After insisting for more than a year that all illegal immigrants “have to go,” Trump met with a newly created panel of Hispanic advisers on Saturday and asked for other ideas — making clear that his position is not finalized, according to two attendees. Any shift would represent a remarkable retreat on one of the Republican nominee’s signature issues.

The meeting prompted attempts by Trump advisers on Sunday to clarify his position. Campaign manager Kellyanne Conway said on CNN that Trump’s stance on mass deportations was “to be determined” but that he will be “fair and humane for those who live among us in this country.” Sen. Jeff Sessions (R-Ala.), a close Trump adviser, said on CBS that the nominee is “wrestling” with the issue but has not changed his position yet.

“People that are here unlawfully, came into the country against our laws, are subject to being removed,” Sessions said. “That’s just plain fact.”

The remarks were the latest in a series of moves by Trump or his aides in recent weeks to alter or shade his position on issues that have been central to his appeal — an effort that has accelerated as he fades in the polls behind Democratic rival Hillary Clinton. The shifts appear aimed at shoring up support among white GOP moderates who have been reluctant to support extreme positions staked out by Trump during the Republican primary, including a massive U.S.-Mexico border wall, deportation of illegal immigrants and a “total” ban on foreign Muslims.

Appearing on political television shows Aug. 21, Donald Trump’s new campaign manager Kellyanne Conway said the Republican candidate just had the best week of his campaign. Conway’s Democratic counterpart Robby Mook defended the Clinton Foundation amid criticism about its acceptance of foreign donations. (Bastien Inzaurralde/The Washington Post)

At the same time, any oscillation carries the risk of alienating Trump’s most loyal supporters, many of whom adore his willingness to buck “political correctness” by laying out brash proposals. Trump has thrived in part by staying vague on most of his policy positions, vaccillating between extreme rhetoric and assurances of reasonableness.

Hillary Clinton’s campaign aides and critics of Trump within his own party have urged voters to focus on the concrete promises and proposals that Trump has made rather than the opaque rhetoric he often employs.

One key case in point is Trump’s position on foreign-born Muslims. In December, Trump issued a written statement — still on his campaign website — calling for a “total and complete shutdown of Muslims entering the United States,” although within days he said it would be temporary and would include a number of exceptions. By spring, he seemed to back away from the controversial proposal, calling it “just a suggestion,” only to double down once again following an Islamic State-inspired mass shooting at an Orlando gay nightclub. Then this summer, Trump stopped using the word “Muslim,” instead saying he would focus on “areas of the world where there’s a proven history of terrorism against the United States” — he wouldn’t say which ones — and implement “extreme vetting.”

“I’m talking about territories now,” Trump told Sean Hannity of Fox News in late July, insisting that his position had not changed but had expanded. “People don’t want me to say Muslim — I guess I’d prefer not saying it, frankly, myself. So we’re talking about territories.”

Rick Wilson, a longtime GOP strategist who strongly opposes Trump and is now working on the campaign of independent candidate Evan McMullin, called Trump’s shape-shifting on such issues “irritating.”

“He lets people fill in the blanks mentally for what they think he’s saying, not what he’s actually saying,” Wilson said. “So when you hear him saying one day: ‘I’m going to ban all Muslims,’ but then you hear him say another day, ‘Well, I’m going to ban the dangerous, bad ones.’ And then you hear him another day saying, ‘I’m going to ban the ones from the bad countries.’ So it always flips, and then the people that are fanatics about Trump just say, ‘Oh, well, he meant the one that I liked.’ ”

A woman in a U.S. flag themed dress poses for photos as GOP nominee Donald Trump speaks in Virginia on Saturday. (Carlo Allegri/Reuters)

Trump has been equivocal on a long list of other issues as well, including the fight against terrorism, abortion and gun control.

On the Islamic State terrorist group, for example, Trump has presented a panoply of options throughout the campaign: Allow Russia to handle the problem. Send in tens of thousands of American troops. “Bomb the s---” out of oil fields controlled by the group and seize the oil. Or just “bomb the hell out of ISIS,” using a common acronym for the group.

Trump has also promised to revive waterboarding of terror suspects, only to say later that he would never force members of the military to break U.S. and international law. Then he said he would change those laws.

On guns, Trump implied that he wants to arm intoxicated club-goers and bar patrons — an idea that concerned even the National Rifle Association — then later insisted he “was obviously talking about additional guards or employees.” He suggested that Japan arm itself with nuclear weapons, then insisted he had never said that. He promised to raise taxes on wealthy individuals like himself, then insisted he never said that.

Trump called for banning abortion and then punishing women who have the illegal procedure, a position he quickly abandoned. He has said that wages are “too high” and “too low,” while calling for both an end to the federal minimum wage and an increase of it. He was opposed to H-1B visas used by skilled foreign workers, then in favor of the program, and then once again opposed.

Trump’s campaign did not respond to a request to clarify his positions on these and other issues. This spring, Trump insisted in an interview with The Washington Post that his positions have not changed at all.

“I mean I feel that I’m very consistent but you must have flexibility,” Trump said, seeming to take two positions on the question. “If you have a position, that doesn’t mean that there is not a better alternative . . . I’m very upfront with people and I will tell people, but I think I’ve been extremely, I think I’ve been steadfast in my beliefs, actually. But with all of that being said, sometimes there is flexibility. Sometimes you want to negotiate.”

Greg Mueller, a GOP strategist who worked on Pat Buchanan’s 1992 presidential campaign, said Trump’s positions have undergone “tweaks” but his big-picture stances on immigration, taxes and the economy have remained consistent — unlike Hillary Clinton, whom he accused of “doing a 180” on trade. Trump’s views should become even clearer as the GOP nominee gives more policy speeches that have been more deeply thought out than a quick answer on cable news, Mueller said.

“Candidates of all stripes running for all sorts of offices, especially national office where they’re dealing with a large breadth of issues . . . they modify or refine positions as campaigns go on or as issues change and we learn new information,” he said.

At the heart of Trump’s campaign is fierce opposition to illegal immigration. Trump has proposed building a mammoth wall along the southern border — so tall that no ladder could ever reach the top, he has said — and then to deport the millions of immigrants illegally in the country but allowing them to apply to reenter legally.

“They have to go,” Trump said on NBC’s “Meet the Press” last year.

This June, Trump expressed hesitation in using the term “mass deportations,” although his aides would not say whether his position had changed. In the meeting Saturday with his Hispanic advisory panel, Trump asked to hear policy ideas — although the campaign said that should not be taken as a sign that Trump has changed his position.

“He addressed the immigration issue himself and said, ‘Look, I know it’s an issue. The biggest problem is the 11 million that are here.’ He asked for our input on how to deal with them,” said Jacob Monty, a Houston-based immigration attorney who handles complex immigration issues for large corporations, including the New York Yankees.

Conway — who was just hired last week amid a campaign shake-up — was asked during an interview Sunday on CNN’s “State of the Union” whether Trump still wants “a deportation force removing the 11 million or so undocumented immigrants.”

“To be determined,” said Conway, who in the past has supported creating a pathway to citizenship for the millions of immigrants illegally living in the United States.

“What he supports is to make sure that we enforce the law, that we are respectful of those Americans who are looking for well-paying jobs and that we are fair and humane for those who live among us in this country,” she said earlier in the interview.

Conway said the candidate will reveal the specifics of his immigration plan “as the weeks unfold.” Trump is expected to give an immigration policy speech on Thursday in Colorado.

Clinton’s campaign responded by listing Trump’s clear calls for mass deportations over the past year and noting his favorable comparison of his plans to “Operation Wetback,” which were mass deportations carried out during the 1950s under President Dwight D. Eisenhower.

“Whether Donald Trump’s immigration plan includes a deportation squad to forcibly remove millions of families from their homes has been asked and answered by the candidate himself time and time again,” Lorella Praeli, Hillary for America’s national Latino vote director, said in a statement. “When someone running for president says he looks upon a plan called Operation Wetback favorably, we should believe him the first dozen times he lays out his intentions.”

Ed O’Keefe contributed to this report.