AILSA CHANG, HOST:
Now, Nielsen is not the only high-level Homeland Security official to lose a job in the last 24 hours. Earlier today, White House press secretary Sarah Sanders announced that Secret Service Director Randolph Tex Alles will be replaced next month after two years on the job. It's just the latest upheaval in the sprawling Department of Homeland Security.
Joining us now to explain what has been going down is NPR national political correspondent Mara Liasson. Hey, Mara.
MARA LIASSON, BYLINE: Hey, Ailsa.
CHANG: So is the departure of the Secret Service director connected to Kirstjen Nielsen's firing?
LIASSON: I think it's connected in one way. President Trump has decided to do a general housecleaning at the Department of Homeland Security. And it's not just Secretary Nielsen or Tex Alles. There are several other DHS leaders who are expected to leave soon, including the general counsel and the head of the U.S. Citizenship and Immigration Services. And these are all people who were brought in by John Kelly when he was the head of DHS before he became the White House chief of staff. And Donald Trump wants to put his own stamp on the agency.
LIASSON: I'm also told by White House officials the Secret Service director was not connected to security questions at Mar-a-Lago. It was in the works before the latest security breach there - Chinese woman with a lot of passports and hard drives.
LIASSON: But - so this is not necessarily directly connected to immigration unlike Nielsen's resignation, which was immigration-related.
CHANG: Well, let's talk about Nielsen's resignation. How much blame are President Trump and his allies putting on Nielsen for the spike in border crossings lately?
LIASSON: Well, the president puts a lot of blame on her for this. They clashed. She really tried hard to advocate for his goals on the border, but she had a hard time turning them into effective policy. Sometimes she would push back and say, this is unconstitutional, or, there are laws preventing you from doing this. But the White House is bracing for bad numbers showing that the surge in illegal border crossings has gone up. It was 76,000 in February. And experts say that it's going to be close to a hundred thousand for March.
LIASSON: So clearly the president's goal of trying to stop immigration - legal, illegal, whatever - is not working.
CHANG: All right, well, Nielsen's being replaced by Kevin McAleenan, who's currently in charge of U.S. Customs and Border Protection. Tell us a little more about him. Is he in the running to become the permanent secretary?
LIASSON: No, he's not. He's a career CBP official. He was already in place when the Trump administration came in. He's not known as an immigration hardliner. As a matter of fact, he's told the Senate that he thought the United States should support governments in Central America to improve economic opportunities there - in other words, to take away the motivation for people to flee. He's also talked about asylum-seekers as vulnerable families, not as scam artists. Sometimes the president describes them that way. But he's not going to have a lot of say in policy. That comes from Trump and his inner-circle of advisers at the White House, particularly Stephen Miller, who has the loudest voice on immigration...
LIASSON: ...Inside the White House.
CHANG: Now, a lot of people are noticing that McAleenan will be the third acting secretary running a major cabinet department. Interior and Defense are also being run by acting secretaries. And I'm not even including the scores of lower-level acting officials in this administration. Is this as unusual as it seems?
LIASSON: Well, it certainly is breaking records for this kind of thing. But Donald Trump has said he likes having acting secretaries. He gives them more flexibility. His critics would say that's 'cause he wants all these people on a short leash. But this is clearly what the president wants.
CHANG: All right, that's NPR national political correspondent Mara Liasson. Thanks so much, Mara.
LIASSON: Thank you. Transcript provided by NPR, Copyright NPR.