WASHINGTON — Eleven days before President Trump erupted in anger at his homeland security secretary in a cabinet meeting on Wednesday, he complained at a rally in Michigan about what he called “the dumbest immigration laws anywhere on earth.”
Six days later, he told the National Rifle Association about “deadly immigration loopholes,” “horrible killer gang members” and “laws that were written by people that truly could not love our country.”
And hours after berating his secretary of homeland security, Kirstjen Nielsen, for failing to secure the border, Mr. Trump headed to Indiana, where he vented that Democrats have given the country “the worst immigration laws in the history of mankind.”
Mr. Trump’s fury at Ms. Nielsen was a long time coming, White House officials said. They described it as part of the president’s longstanding desire to close the United States’ borders and part of his increasing belief that his administration is moving too slowly to make good on the central promise of his 2016 presidential campaign.
“The president has every right to be frustrated,” said Dan Stein, the president of the Federation for American Immigration Reform, which advocates tough restrictions on immigration. “He wants people around him who can get around the bureaucracy and overcome the deep state and make things happen.”
But Frank Sharry, the president of America’s Voice, a pro-immigration group, said that Mr. Trump’s anger revealed ignorance about the cyclical nature of illegal border crossings into the United States.
Early in the president’s term, Mr. Sharry noted, Mr. Trump repeatedly cited his own tough messaging and initial actions on immigration — including announcing a travel ban from predominantly Muslim countries — as the reason for a big drop in people crossing the Mexican border.
“You see what’s happened: 61 percent down now in terms of illegal people coming in,” Mr. Trump said at a union conference in April 2017. “Way, way down in terms of drugs pouring into our country and poisoning our youth. Way down.”
Those numbers have since risen to more normal levels, pro-immigration groups speculate, because illegal immigrants were initially stunned by the president’s early messaging but are now disregarding it. In March and April this year, about 50,000 people crossed from Mexico into the United States illegally, about three times the number who did so a year earlier.
“He doesn’t understand what’s happening,” Mr. Sharry added. “He thinks that he should be able to issue dictates and yell at his staff and make the world move. But this is a 20-year trend.”
Hard-liners on immigration say Mr. Trump’s anger is partly explained by a suspicion inside the West Wing that Ms. Nielsen, who served on the Homeland Security Council in the George W. Bush administration, is not sufficiently committed to Mr. Trump’s agenda of tougher immigration policies.
In testimony to a congressional committee on Tuesday, the day before the president’s tirade at the cabinet meeting, Ms. Nielsen urged people seeking asylum to present themselves at United States ports of entry rather than trying to sneak into the country.
Aides say she was trying to send a strong message about not breaking the law. But many hard-line conservatives viewed her statement as an invitation to asylum seekers, many of whom end up living in the United States for years while their claims are adjudicated.
An all-caps headline in Breitbart News screamed: “EXPERT: DHS SEC KIRSTJEN NIELSEN MADE ‘COLOSSAL MISTAKE’ IN ‘INVITING’ FOREIGN NATIONALS ‘TO COME TO PORTS OF ENTRY.’”
Mark Krikorian, the executive director of the Center for Immigration Studies, another hard-line group, said Ms. Nielsen’s approach to border security is less like Mr. Trump’s campaign messaging and more like the moderate approach taken by Mr. Bush.
In her statement after Mr. Trump’s comments were made public, Ms. Nielsen said: “I share his frustration. Border security is the most basic and necessary responsibility of a sovereign nation. These are complex issues and I will continue to direct the department to do all we can to implement the president’s security-focused agenda.”
Mr. Trump remains angry that the wall he promised along the southern border with Mexico is not yet funded or under construction — and he was so upset about the issue in March that he threatened to veto a $1.3 trillion spending plan because it included no money for the project.
He is also unhappy with what he calls legal loopholes — laws or policies that in his view are too lax but remain on the books.
“I understand his frustration because the reality is that there’s only so much a president can do without the help of Congress,” said Roy Beck, the president of NumbersUSA, a conservative immigration group.
One of those loopholes is a policy that allows families who cross the border illegally to remain together while their case is decided. Mr. Trump has pushed Ms. Nielsen and others in the government to adopt a policy that separates parents from their children if they cross into the United States illegally.
In an interview with National Public Radio this week, John F. Kelly, the White House chief of staff, said that most of the people who cross the border illegally “are not bad people. They’re not criminals. They’re not MS-13” gang members.
“They’re overwhelmingly rural people in the countries they come from,” Mr. Kelly said.
Conservatives say the president could do more to dissuade immigrants from coming to the United States in the first place. Mr. Beck’s group has urged Mr. Trump to aggressively campaign for Congress to require businesses to use “e-verify,” a technical system to check for citizenship before hiring a worker.
But officials at the Department of Homeland Security say the administration has not been sitting idly by.
Tyler Houlton, a spokesman for the department, said that under Ms. Nielsen, enforcement has increased, the National Guard has been deployed to the border and vetting of immigrants has tightened. The department also terminated visa programs that granted temporary status to some immigrants for decades and pledged to refer for prosecution 100 percent of those arrested crossing the border illegally.
“This is a record of success,” Mr. Houlton said, adding, “But we are committed to doing more.”