Chip Somodevilla/Getty Images The New York Times reported President Donald Trump's "zero-tolerance" policy that separates families at the US-Mexico border was the work of White House senior policy adviser Stephen Miller. Miller pushed the policy to fruition after March's increase in illegal immigration, which Trump touted as a top priority in his 2016 campaign. The policy has drawn criticism from lawmakers in and outside of the Trump administration. President Donald Trump's "zero-tolerance" policy that separates families at the US-Mexico border was the work of White House senior policy adviser Stephen Miller. The New York Times reported the origin of the controversial policy on Saturday.