Outgoing Department of Homeland Security Secretary Kirstjen Nielsen speaks to...

Outgoing Department of Homeland Security Secretary Kirstjen Nielsen speaks to the media Monday outside her home in Alexandria, Va. Credit: Getty Images/Mark Wilson

With Kirstjen Nielsen leaving as Homeland Security secretary, a much bigger story is hidden in plain sight.

That is, the White House implicitly admits with her ouster that two years of posturing has failed to force changes regarding refugees and asylum.

Without knocking President Donald Trump, Nielsen wrote in her resignation letter:

"I hope that the next Secretary will have the support of Congress and the courts in fixing the laws which have impeded our ability to fully secure America’s borders and which have contributed to discord in our nation’s discourse.”

She didn't note that Trump's repeated public threats to close the southern border brought warnings from Nielsen's department and others of potential economic calamity.

His tensions with Nielsen, a protégé of former White House chief of staff John Kelly, seem to leave Trump nowhere on a workable immigration policy.

Migration northward is on the rise. U.S. Customs and Border Protection has reported 66,450 persons arrested between ports of entry in February, the highest monthly figure in 10 years.

There is no sign that this is because the officials have gotten better at catching border jumpers. Projections for March and the months to come are expected to exceed 100,000. People are fleeing Central American poverty and violence.

Predictably by now, Trump in a crisis rotates a pointed Twitter finger in many directions.

He blames foes of his "big beautiful wall," immigration advocates, courts, opponents of splitting up migrant families, "criminals" invading the U.S., prior Republican presidents, prior Democratic presidents, and, of course, the governments of Mexico, El Salvador, Honduras and Guatemala, on and on.

Now and then the finger points to Congress, where solutions really do lie.

In January, during Trump's futile wall-funding shutdown, Democrats in the House offered to support funding for alternative measures. They spoke of billions for additional personnel, technology and other enhancements. Practical or not, these entreaties received no embrace from Trump & Co., which seems averse to negotiating with either house.

Clearly the administration is short on the resources needed to process migrants seeking asylum as refugees. But anything that departs from a bitter "us-versus-them" pose seem not to interest the president.

Perhaps there is a local historic warning here. Under Mayor Ed Koch in the 1980s, as high crime staggered American cities, he shouted knowingly in vain for Albany to restore the death penalty, but police numbers shrank because of fiscal constraints.

The Koch administration left the city with sky-high crimes rates and crack use rampant.

Coping with a tough situation might not provide exciting material for big rallies. If Trump is trying to cut an emergency deal with Congress — which under the Constitution must sign off on any big spending and immigration-law changes — he might first wish to establish credibility with lawmakers of both political parties.

Instead Trump shares strange border tales of prayer rugs found in the desert, left-wing conspiracies to fund "caravans," smuggling of fentanyl, which is usually done through the mails — plus the fake news that immigrants facing removal proceedings never show up at hearings even as the Justice Department says most of them do.

Telling lies and suspect stories won't jump-start serious talks with Congress, several of whose members he jeers with silly nicknames.

If the administration has a strategy to reform immigration laws, it has yet to come clear. Replacing Nielsen might not matter.