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In a Dec. 5 meeting between President-elect Donald Trump's transition team and Department of Homeland Security officials, Trump's representatives requested a broad selection of documents and analysis, including the federal resources available to build border walls, a list of all executive orders President Obama issued regarding immigration, and any changes made to files on foreign-born adults brought to the U.S. illegally as children and granted temporary protections by Obama, Reuters reported Tuesday, citing an internal DHS memo.

A DHS official told Reuters that the department interpreted the request about changes made to migrant records, including for reasons of protecting civil rights or civil liberties, as a signal to federal workers not to tamper with data to protect immigrants, especially those protected by the DADA program, whose applications include addresses and other information that could potentially be used to deport the young immigrants if Trump reversed Obama's policies. The DHS memo also suggested that Trump wants to ramp up a program of aerial surveillance by National Guard pilots that was downsized under Obama but is popular with conservatives.

The DHS also provided the Trump team with cost estimates for building fencing along both America's southern and northern borders, and a Canada wall — which Trump has not pushed for — is considerably cheaper, at $3.3 billion along 452 miles, or $4.1 million per mile. The Mexico border wall, which Trump has promised to build, would cost $11.37 billion for 413 miles of fencing, or $11.2 million per mile, because it would be aimed at keeping out pedestrians, not just vehicles.