The president said on Twitter that Mr McAleenan has done an outstanding job and border crossings are down.
While Trump said he would be nominating a new acting secretary next week, from "many wonderful candidates", the position would normally pass to the current acting Deputy Secretary, David Pekoske - a retired US Coast Guard vice-admiral who now serves as head of the Transportation Security Administration (TSA). He tweeted he has "wonderful candidates" to fill the position.
McAleenan had only been in the position since April, and was the fourth person to lead the department in two years. McAleenan told The Associated Press that he was leaving on his own terms, which would be unlike other top administration figures pushed out during Trump's tenure. He was appointed acting secretary to replace Kirstjen Nielsen after she quit.
McAleenan tweeted that he had worked - with the president's support - to stem the crisis and that he would help ensure a smooth transition.
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On the company's website - "mschf" says more will be available October 22, and subsequent 2nd and 4th Tuesdays of each month. " Jesus Shoes " are made with 100% frankincense wool (get it?), while the laces are strewn with a crucifix.
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In wins, they've served as the springboard for offense. "I don't think there is anything major structurally wrong with him". Through the first 10 minutes against Vegas, it looked like much of the same as they fell behind 2-0.
Moreover, with the numbers of undocumented immigrants apprehended or turned away at the border coming down for the fourth consecutive month - 52,546 in September, a 65% drop from May - the lack of crisis is dissuading members of Congress to act and compromise.
Bennie Thompson, the Democratic chairman of the House Committee on Homeland Security, called McAleenan's exit an "ouster" and said Trump must urgently appoint a permanent replacement. A source familiar with McAleenan's thinking says that he is proud of working with the governments of Mexico and the three Central American "Northern Triangle" countries - El Salvador, Guatemala and Honduras - to crack down on human smugglers and block caravans heading north.
Bersin credited McAleenan's close work with Mexico for helping lower border arrests from May peaks.
McAleenan weathered the storm, but Mark Morgan, acting head of CBP, and Ken Cuccinelli, acting head of U.S. Citizenship and Immigration Services, vocal supporters of Trump's immigration policies, have since then become the face and mouth of the department, while McAleenan took a public back seat.
Homeland Security has been the cabinet post with the highest turnover in the Trump administration at this point.