WASHINGTON ― In a stunning announcement Monday afternoon, acting Attorney General Sally Yates said the Justice Department won’t defend President Donald Trump’s executive order blocking all refugees and certain foreign nationals.

“I am responsible for ensuring that the positions we take in court remain consistent with this institution’s solemn obligation to always seek justice and stand for what is right,” Yates, an appointee of former President Barack Obama, wrote to Justice Department lawyers, the New York Times first reported. “At present, I am not convinced that the defense of the executive order is consistent with these responsibilities nor am I convinced that the executive order is lawful.”

The announcement from Yates delivers a symbolic blow to the executive order Trump signed on Friday suspending all refugee resettlement for 120 days, halting Syrian refugee resettlement entirely and temporarily barring entry of nationals from seven Muslim-majority countries: Iran, Iraq, Libya, Somalia, Sudan, Syria and Yemen.

Before Yates’ letter, the Justice Department said that the Office of Legal Counsel at DOJ had cleared the language of Trump’s executive order. But as Yates made clear in her letter, that review was focused on the narrow question of whether it is lawful on its face and properly drafted and “does not address whether any policy choice embodied in an Executive Order is wise or just.”

Trump called Yates “an Obama A.G.” in a tweet not long after her letter became public, and said that Democrats were “delaying [his] cabinet picks for purely political reasons.”

The Democrats are delaying my cabinet picks for purely political reasons. They have nothing going but to obstruct. Now have an Obama A.G. — Donald J. Trump (@realDonaldTrump) January 31, 2017

Trump advisor Stephen Miller said on MSNBC’s “For The Record” that it was “sad” that there were people “refusing to enforce our laws,” and knocked Yates and others for objecting to Trump when they didn’t object to Obama’s immigration decisions.

“Now you have us using and utilizing and enforcing our laws and you have the same people who were silent then now engaging in misguided political protests,” Miller said.

Trump’s order faces multiple lawsuits, and several courts had already issued orders that led to the release of some individuals detained due to the executive order. But the refusal of the Justice Department to defend the order leaves it in legal limbo.

Also in limbo is Yates’ immediate fate at the department. A week before leaving office, Obama signed an executive order providing for a succession line at the Department of Justice once Attorney General Loretta Lynch left her post. Under that order, Yates, who is a longtime career prosecutor at the DOJ, would serve as acting attorney general. Trump agreed to keep her on the post until the confirmation of his nominee, Sen. Jeff Sessions (R-Ala.).

Trump has the power to fire Yates and very well could, though that would send a potentially damaging signal for how he views the department’s prosecutorial independence. It would also leave the department without any officials authorized to sign warrants for foreign surveillance.

There was no immediate comment from the White House.

However, Yates’ decision would almost certainly be reversed as soon as the Senate confirms Sessions.

At least one Democrat is already sticking up for Yates. Sen. Richard Blumenthal (D-Ct.) said in a statement that she “demonstrated genuine grit and grace in standing strong for the rule of law.”

Sally Yates: person of integrity/attorney with great legal skill. Has served this nation with distinction. Her judgment should be trusted. — Eric Holder (@EricHolder) January 31, 2017

Meanwhile, Democrats continued to attack the order on Monday, introducing bills in both chambers to halt its implementation. Republicans blocked votes on it, but Democrats clearly feel they have the public on their side and aren’t dropping the issue. They led an evening rally outside the Supreme Court demanding an immediate end to the ban on refugees and travelers. Police closed down the street in front of the court to accommodate the hundreds of people who showed up with signs, and ready chants, in support of Democrats’ efforts.

One of those people was Bill Sanderson, who stood in the cold with his wife and their 2-year-old son.

“I’ve got a baby on the way,” said Sanderson, 40, motioning to his pregnant wife, Lise Clavel. “And I’ve got this guy who’s 2 years old. I want him to see what it looks like when people feel something strongly. Whatever he comes to believe, I want him to feel this.”

Clavel said she felt obligated to lend her voice at the rally because she fears Trump’s agenda will leave the country worse off for minorities and women.

“We don’t know who is on the way, but especially if it’s a little girl on the way, we just haven’t seen something like this in our country, in our lifetimes,” she said, choking up. “And it’s kind of scary.”

SAUL LOEB via Getty Images

Trump lacks many strong allies among Republicans. Only a small number released statements applauding the order over the weekend, while a growing number have said they are concerned about it. Some have claimed it was the wrong move entirely, and a potentially dangerous one that could be used by terrorist recruiters. But many others objected more to its implementation, which led to the detention in airports of many people with valid visas and even green cards, and both Congress and the agencies tasked with enforcing the order scrambling to figure out how it would work.

A major problem between Trump and congressional Republicans is the fact that many say the order was done without the president’s team consulting them at all ― outside the norm for a major and controversial policy change. It’s tough for lawmakers to mount a rousing defense of an order they hadn’t seen until the day it was signed ― or one they still have questions on that the administration hasn’t answered.

Sen. Marco Rubio (R-Fla.) said that his staff was told by the State Department that it “was ordered not to talk to Congress about this issue.”

“We were told that the directive was that they were not to share any information today, and ... I suppose it’s because I’m not clear what they’ll tell us yet,” Rubio told reporters. “But that cannot be a permanent position. We expect answers here fairly soon because we have constituents calling.”

UPDATE: White House press secretary Sean Spicer said Monday night on Twitter that Yates “has been relieved” from her job and that Dana Boente, U.S. attorney for the eastern district of Virginia, has been named acting attorney general.

Read the full text of Yates’ letter:

On January 27, 2017, the President signed an Executive Order regarding immigrants and refugees from certain Muslim-majority countries. The order has now been challenged in a number of jurisdictions. As the Acting Attorney General, it is my ultimate responsibility to determine the position of the Department of Justice in these actions.

My role is different from that of the Office of Legal Counsel (OLC), which, through administrations of both parties, has reviewed Executive Orders for form and legality before they are issued. OLC’s review is limited to the narrow question of whether, in OLC’s view, a proposed Executive Order is lawful on its face and properly drafted. Its review does not take account of statements made by an administration or it surrogates close in time to the issuance of an Executive Order that may bear on the order’s purpose. And importantly, it does not address whether any policy choice embodied in an Executive Order is wise or just.

Similarly, in litigation, DOJ Civil Division lawyers are charged with advancing reasonable legal arguments that can be made supporting an Executive Order. But my role as leader of this institution is different and broader. My responsibility is to ensure that the position of the Department of Justice is not only legally defensible, but is informed by our best view of what the law is after consideration of all the facts. In addition, I am responsible for ensuring that the positions we take in court remain consistent with this institution’s solemn obligation to always seek justice and stand for what is right. At present, I am not convinced that the defense of the Executive Order is consistent with these responsibilities nor am I convinced that the Executive Order is lawful.

Consequently, for as long as I am the Acting Attorney General, the Department of Justice will not present arguments in defense of the Executive Order, unless and until I become convinced that it is appropriate to do so.