... all five officials who spoke with theWashington Examiner confirmed McAleenan's decision to go rogue and stymie the operation was what prompted the White House to call off the 10-city operation. (snip)The sources said only a small number of people in the White House, ICE, and DHS were even aware of the plan’s details, including which cities, the date and time, and who would be targeted.

Two officials said the acting secretary, who was promoted internally in April, had fought for months during closed-door discussions with White House officials, the former acting ICE Director Ronald Vitiello, and the new acting ICE Director Mark Morgan against the plan, which they noted was similar to one the
B.O. regime carried out in 2015.
"I know he has not approved of this operation for months," one person familiar with those private conversations said during a phone call Saturday night. "The president wouldn’t leak that. ICE wouldn’t leak that. There’s only a few people involved in these discussions ... The only one who could have shared the details of those operations were Kevin."

"That’s our belief," a second official said when asked if McAleenan was behind the leak. "The secretary was not supportive from day one."
The first official said McAleenan may have leaked it so that he could "be the martyr" in the face of anticipated blowback in the future.