Mr. Mattis was not consulted by the White House during the preparation of the executive order on immigration, which temporarily blocks Iraqi citizens from entering the United States for 90 days. Six other predominantly Muslim countries are covered by the edict: Syria, Yemen, Libya, Somalia, Sudan and Iran.

The White House has argued that the temporary ban is needed so that the United States can develop procedures for the “extreme vetting” of travelers from nations that have been stricken by terrorism. Officials said that the Iraqis who will be put on the Pentagon list have already undergone a stringent form of vetting: serving with the United States military in combat.

Schumer’s a ‘no’ on nominations, across the board

Senator Chuck Schumer of New York, the Democratic leader, approached his new job as the anti-Harry Reid: Yes, he would fight President Trump where he needed to, but he made it clear he really wanted to find areas of cooperation.

That may not be happening.

Driven by the executive order on immigration and by the vociferous demands of the increasingly activist Democratic base, Mr. Schumer announced on Monday that he would oppose President Trump’s nominees pretty much across the board: No on Betsy DeVos for education secretary, Rex Tillerson for secretary of state, Senator Jeff Sessions for attorney general, Representative Mick Mulvaney for budget director, Representative Tom Price for secretary of health and human services, Steven Mnuchin for treasury secretary, Scott Pruitt for E.P.A. chief and Andy Puzder for labor secretary.

Cooperation, it seems, is over.

“After the first week of the Trump presidency it’s clear our country is at a cross roads. In his first week in office the president has stomped over our proud American tradition of welcoming immigrants and refugees, trafficked in alternative facts, and is attempting to fill his cabinet with billionaires and bankers. What kind of country do we want to be: one that helps the middle class and those struggling to get there or one that further rigs the system in favor of the special interests?”

It might not have helped that Mr. Trump mocked Mr. Schumer for his tearful denunciation of his immigration order.

“I noticed Chuck Schumer yesterday with the fake tears,” Mr. Trump told reporters on Monday during a meeting with small-business leaders. “I’m going to ask him who was his acting coach, because I know him very well. I don’t see him as a crier.”

Calm down, Trump says, few were detained

Besieged by criticism, with chaos at international airports mounting and protests proliferating, Mr. Trump defended the aftermath of his executive order halting immigration from the seven countries, saying that problems at airports were the fault of a Delta Airline computer error.