U.S. President Donald Trump fired Sally Yates, the acting attorney-general, after she told federal prosecutors not to defend his administration’s refugee ban, a policy that is threatening to provoke a full-blown political crisis.

Ms. Yates sent a letter on Monday to Justice Department lawyers in which she questioned Mr. Trump’s executive order. Hours later, Mr. Trump named her replacement: Dana Boente, U.S. Attorney for the Eastern District of Virginia. Ms. Yates “betrayed the Department of Justice by refusing to enforce a legal order designed to protect the citizens of the United States,” the White House said in a statement. “It is time to get serious about protecting our country.”

The abrupt firing is the latest chapter in the battle over Mr. Trump’s immigration ban, which has sparked a forceful backlash from across U.S. political and business life. Mr. Trump, however, is vowing not to alter course.

On Monday, former president Barack Obama added his voice to those expressing concern about the executive order signed by Mr. Trump, declaring support for protesters through a spokesman.

On the opposite side of the political spectrum, a representative for conservative billionaires Charles and David Koch has called the ban “wrong” and “counterproductive.”

Athletes and Nobel Prize winners, university presidents and film stars, Starbucks and Goldman Sachs, Ford Motor Co. and Netflix, Democrats and a handful of Republicans have all criticized Mr. Trump’s executive order, which he signed on Friday.

But despite the chorus of condemnation, the pressure points on Mr. Trump are limited. A wide majority of Republicans in Congress support the President’s move to suspend all refugee admissions, block Syrian refugees indefinitely and deny entry to visa holders from seven Muslim-majority countries.

Democrats in the U.S. Senate are vowing to introduce measures to rescind the ban as early as Monday evening. But for now they do not appear to have the numbers to move such legislation forward, even if the eight Republican senators who have voiced opposition to Mr. Trump’s ban all decided to cross the aisle and support their effort.

On the weekend, federal judges in four states issued orders that prevented the U.S. government from deporting people already in the country who held valid papers. The rulings were limited in nature and left the bulk of Mr. Trump’s order intact, which means an unknown number of people – refugees and visa holders – remain unable to travel to the United States.

Among the many who are stuck: Vian Dakhil, a human-rights campaigner from Iraq’s persecuted Yezidi community who was due to accept an award at the U.S. Capitol next week, according to The Washington Post; a 12-year-old Yemeni girl with a valid visa whose parents are U.S. citizens; Asghar Farhadi, an Iranian film director nominated for an Oscar, who said he would not travel to the United States for the awards in March because of the ban.

On Monday, Sean Spicer, Mr. Trump’s press secretary, issued a staunch defence of the ban, saying it was necessary in order to put the security of Americans first.

“I understand that [it] is an inconvenience, but at the end of the day, that is a small price to pay,” he said.

Mr. Spicer was asked about a group of dozens of U.S. diplomats who have expressed their opposition to Mr. Trump’s ban by signing what is known as a “dissent memo,” a long-standing mechanism for State Department employees to voice disagreements with government policy. Mr. Spicer responded that federal employees should “either get with the program or they can go.”

According to a running tally maintained by the Washington Post, 24 Republican members of Congress publicly oppose the ban. Another 36 have expressed reservations about the way it was implemented. At least 80 have voiced their support.

But beyond Republicans in Congress and Mr. Trump’s supporters, the discomfort with the ban has deepened. On Sunday, Brian Hooks, who co-chairs the network of conservative political organizations supported by Charles and David Koch, said the ban is “the wrong approach and will likely be counterproductive,” according to The Associated Press.

The United States has received tremendous benefits from its history of welcoming people from all cultures, Mr. Hooks continued. “This is a hallmark of free and open societies,” he said.

On Monday, in his first public statement since leaving office, Mr. Obama said he was encouraged by the protests that have erupted across the country in response to Mr. Trump’s ban.

Mr. Obama “is heartened by the level of engagement taking place in communities around the country,” his spokesman said. “Citizens exercising their Constitutional right to assemble, organize and have their voices heard.”

While the protests may not have any impact on the Trump administration, they are putting significant pressure on Democrats in Congress to take a more confrontational approach. Democratic senators who addressed protests on the weekend were pressed to explain why they had voted to confirm any of Mr. Trump’s cabinet picks.

On Monday, Senator Chuck Schumer of New York, the most senior Democrat in the chamber, announced that he would ask every one of Mr. Trump’s cabinet nominees to issue a public statement on their views of the immigration ban. He said he would seek to delay a vote to confirm Rex Tillerson, the former chief executive of Exxon Mobil and Mr. Trump’s pick for secretary of state, in order to ascertain Mr. Tillerson’s position on the executive order.

By charging ahead with the order, Mr. Trump created not just chaos at airports and anger in the streets but a moment of political turmoil the likes of which the United States has not seen in decades. Heather Cox Richardson, a historian at Boston College, wrote recently that the ban was a “shock event” which had the power to destabilize U.S. politics in unpredictable ways.

JOANNA SLATER
U.S. CORRESPONDENT — The Globe and Mail
Published Monday, Jan. 30, 2017 8:01PM EST
Last updated Tuesday, Jan. 31, 2017 8:54AM EST