Responsibility for national border security legally - and logically - belongs to the national government. But the Obama administration's persistent abdication of that duty has moved numerous states, including South Carolina, to pass immigration laws of their own.

And Texas Gov. Rick Perry announced Monday that he will send up to 1,000 of his National Guard troops to the Lone Star State's border with Mexico in an effort to ease an ongoing crisis.

Gov. Perry fairly accused the White House of providing only "lip service" on belatedly securing the border in the wake of a massive northward flow of more than 50,000 unaccompanied minors, mostly from Central America, into the U.S. since the start of last October.

He said the National Guard personnel would be used as a "force multiplier" to help the Texas Department of Public Safety "combat the brutal Mexican drug cartels that are preying upon our communities," adding, "I will not stand idly by while our citizens are under assault and little children from Central America are detained in squalor. We are too good of a country."

White House spokesman Josh Earnest offered this predictably dismissive response:

"What we're hopeful is that Gov. Perry will not just take these kinds of steps that are generating the kind of headlines I suspect he intended, but will actually take the kinds of steps that will be constructive to solving the problem over the long term. To be specific that means that we hope that Gov. Perry will support the supplemental appropriations request that this administration put forward a few weeks ago and that Gov. Perry will use his influence with congressional Republicans in Congress and urge them to stop blocking comprehensive bipartisan legislation in the House of Representatives."

Yet most of the $3.7 billion that the president is requesting would go to handling the huge influx of minors, not to border security. And the administration's actions over the past month have not matched its assurances that it's moving toward sending the vast majority of those unaccompanied children back to their home countries, where they belong.

As for immigration reform, the administration's protracted neglect of border security has severely undermined bipartisan attempts to achieve it.

Yes, the U.S. Border Patrol reports that apprehensions of undocumented minors coming across the southern border have declined from 355 a day last month to 150 or less per day in recent weeks. Still, at a rate of 150 per day, that's 4,500 per month.

The unprecedented flood of children from Central America appears to have at least two root causes. Drug-related gang violence in El Salvador, Guatemala and Honduras has taken control of many communities where parents are prepared to pay smugglers as much as $3,000 a head to bring their children to the U.S., according to State Department officials' testimony to Congress.

And President Obama's 2012 executive edict barring deportation of illegal immigrants who entered our nation as children evidently left the impression that any minor coming into the U.S. would get permanent resident status.

Beyond those incentives, a law enacted in 2008 to deal with illegal trafficking in humans provides special treatment for children from countries that don't border the U.S. They are entitled to a hearing before a judge and consultation with an advocate, and may be represented by counsel.

Gov. Perry and others warned the president two years ago about the risk of sending the wrong message with his executive edict on illegal immigrants who entered the U.S. as children. Then early this year, as the rate of apprehensions of unaccompanied children began to climb steeply early this year, the White House was again alerted to the problem by the Department of Homeland Security.

Sen Barbara Mikulski, D-Md., added her voice to the rising alarm in April. And many other congressional Democrats have expressed frustration over the ongoing border crisis.

Yet Mr. Obama waited until July 8 to request that supplemental appropriation to deal with it.

So while the federal government is the proper entity to handle border enforcement, the Obama administration's failure to do so has left a dangerous void.

And you can't blame the states, including Texas, for trying to fill it.