And while she may not have been aggressive enough for Trump, or Miller, Nielsen will forever remembered as the person who ran DHS during one of the darkest moments in US history. An official for US Customs and Border Protection named Kevin has been plucked to replace Nielsen.
When pressed, one White House official said there was a feeling in the West Wing that it was "just time" for Trump and Nielsen to part ways after bumping heads on numerous occasions during her 16-month tenure.
The people described mounting frustrations on both sides, with Trump exasperated at the situation at the border and Nielsen frustrated by White House actions she felt were counterproductive.
Tear gas was used to disperse hundreds of Central American migrants attempting to seek asylum through the border city of Tijuana in November 2018.
"If we're going to work our way through this problem, being tough is not a strategy, it's a soundbite".
She went into the White House on Sunday to meet with Trump not knowing whether she'd be fired or would resign.More news: Verizon launches 5G service in Minneapolis, Chicago
On Friday, he called for Congress to "get rid of the whole asylum system" and get rid of immigration judges, and criticized a long-standing federal court decree mandating certain standards of care for migrant children.
[W] ith almost 100,000 migrants apprehended by Border Patrol agents along the US-Mexico border in March, Trump is yet again ruminating angrily and obsessively over immigration, riffing in speeches about telling migrants "we're full" and "go back". Vitiello, a Border Patrol guard, had been awaiting confirmation by the Senate.
A USA judge on Monday halted the administration's policy of sending some asylum seekers back across the border to wait out their cases in Mexico, a policy it said last week it planned to expand.
Poverty and gang violence in Honduras, Guatemala and El Salvador is largely responsible for the exodus. During her time as Homeland Security secretary, she oversaw widely condemned policies including the forcible separation of families and the caging of children at the southern border.
Delaware Democrat Chris Coons said Monday that what is "striking is how numerous secretaries of the largest departments of this government are acting at this point".
Thousands of young children were taken from their parents and held in separation facilities.
Nielsen also advocated for strong cybersecurity defense and often said she believed the next major terror attack would occur online - not by planes or bombs. I think that's not what she'll be known for. "And it, frankly, has to raise the question for anyone who's offered a Cabinet opportunity [from] President Trump, whether their reputation will survive".