Central American children have entered the United States in large numbers in recent weeks, raising a severe housing challenge.

Their mass entry has also produced another political obstacle to passing comprehensive immigration reform legislation. Opponents of the initiative reasonably point to this latest border problem as additional evidence of the Obama administration's lack of credibility on the issue.

Meanwhile, those children are being housed at assorted shelters, including military facilities in Texas, Arizona, California and Oklahoma.

As Friday's Los Angeles Times reported from Mission, Texas: "The Rio Grande Valley has become ground zero for an unprecedented surge in families and unaccompanied children flooding across the Southwest border, creating what the Obama administration is calling a humanitarian crisis as border officials struggle to accommodate new detainees. Largely from Central America, they are now arriving at a rate of more than 35,000 a month."

Why so many so quickly?

From last Thursday's Washington Post: "Fleeing gang violence and poverty, and driven in part by the belief that Central American women and children will not be deported, many of the migrants are not trying to sneak into the country but are crossing in plain sight."

The U.S. Border Patrol even acknowledged to The Arizona Republic last week that it has flown hundreds of the immigrants from Texas to Tucson and Phoenix, then dropped them off at Greyhound bus stations. Arizona officials have justifiably protested this irresponsible practice.

Numerous Republican lawmakers have cited, as a motivating factor for this incoming tide of humanity, President Barack Obama's executive edict deferring deportation of undocumented immigrants brought to the U.S. as children.

As Sen. Jeff Flake, R-Ariz., told Homeland Security Secretary Jeh Johnson during a Judiciary Committee hearing last week: "Word like this spreads, and word spreads that there will be a review of deportations. There is a perception of lax enforcement that will allow them to get a foothold here."

Mr. Johnson countered that the perception is misplaced - that the president's order actually doesn't apply to these particular immigrants.

But those people streaming into the United States evidently don't realize that. And their continuing migration into our nation strengthens the assumption that the administration has no intention of fulfilling its pledge to bolster border security as a condition of immigration reform.

That cause already is in serious trouble on Capitol Hill. Most analysts are citing voters' concerns about immigration reform a major factor in House Majority Leader Eric Cantor's upset loss to Randolph-Macon economics professor David Brat last week in Virginia.

Clearly, if the president and other advocates of a sweeping immigration overhaul are serious about moving one through Congress this year (or ever), federal border enforcement must be intensified.

And beefing up the federal effort to stem the rising, incoming tide of children from Central America is an obvious place to start.