The split between Republicans and Democrats over how to define a “secure border” has never been more apparent, as a massive surge of illegal immigrants crosses the U.S.-Mexico line.

The White House and Republican lawmakers can't even agree that the dramatic increase in undocumented immigrants from Central America, particularly children, is a border security problem.

According to the White House, the biggest problem is a backlog in cases at overwhelmed immigration courts, not the number of Border Patrol officials being deployed to apprehend illegal immigrants.

“The fact is that last year 360,000 individuals who are attempting to cross the border were detained and removed from this country by existing resources,” said White House press secretary Josh Earnest. “So what that indicates is that there is already a robust effort on the border to secure this country and enforce our immigration laws.

“I think what’s being overburdened by this are actually the immigration courts, right?” he added.

Administration officials said that as of June 15, 52,000 unaccompanied children had been apprehended along the southwest border this year.

The White House is using that figure to argue that its border-enforcement capacities are not the problem — the more vexing issue, they say, is what to do once an undocumented immigrant is detained.

Critics, however, counter that the tens of thousands of cases in just the last few months prove that the Border Patrol is overwhelmed.

“It's absolutely a border security issue. Our strategy isn't working,” said Shawn Moran, vice president of the National Border Patrol Council, a labor union for border patrol agents. “The agents are definitely overwhelmed — 45 percent of the agents are doing processing and administrative duties, which leaves some stations so overburdened."

However, some analysts said the debate is far too complex to focus exclusively on a lack of patrol agents.

“I don't think it's about the Border Patrol,” said Audrey Singer, a senior fellow at the Brookings Metropolitan Policy Program who focuses on international migration. “People are walking right up to Border Patrol agents and turning themselves in. They are thinking about the lag time [before they have to appear in court].”

“We have a separate set of policies around unaccompanied minors,” she explained. “It becomes more like a humanitarian and refugee process.”

Critics also contend that a big part of the problem stems from the immigrants being released until their court dates, which they skip.

“We can have a million judges, but if we continue to release people, the pipeline is going to flow,” Moran said.

The Obama administration has not provided figures for the number of illegal immigrants who did not show up for scheduled judicial hearings. For his part, Moran argues that people from Central America have little fear of being caught because they can simply disappear when they receive a court summons.

In a hearing on Capitol Hill on Tuesday, Department of Homeland Security Secretary Jeh Johnson said he reassigned 115 Border Patrol members from less active areas to the Rio Grande Valley, ground zero for the humanitarian crisis. And the DHS secretary said he would consider sending 150 additional agents to the area.

The Obama administration has opened extra detention facilities along the border and sent more judges and staffers to handle the backlog in immigration cases. Federal officials also are sending children to various centers nationwide amid the housing shortages.

Conservatives see that approach as more of a short-term fix than an actual solution.

The administration argues that it can't simply round up minors and send them back to their home countries, in most cases, Central American nations. Under the law, they say, the minors must be turned over to the Department of Health and Human Services, initiating an often lengthy and burdensome review process.

The Obama administration estimates it will catch 90,000 unaccompanied minors attempting to cross the Mexican border this fiscal year. Fewer than 2,000 children were sent back to their home countries last year, according to the Associated Press.

Surveys have shown that many in Central American countries believe that minors who cross the border will be allowed to stay in the wake of an executive order by President Obama to defer the deportations of certain Dream Act-eligible illegal immigrants. None of the immigrants who recently crossed the border are eligible for that program, the White House says.

Despite that warning, the growing calculation by many illegal immigrants is that the bureaucratic maze will help them avoid prosecution.

Over the past decade, the number of Border Patrol agents has doubled to more than 21,000 — a figure that would increase, the White House says, if the GOP-controlled House passed an immigration reform bill. And the president has repeatedly argued that the border has never been more secure.

Still, the crisis rages on along the U.S.-Mexico border. And critics contend that without a stronger border security commitment from the Obama administration, the situation will become even grimmer.

“The Border Patrol still has fewer people in the entire patrol than there are cops in New York City,” said Mark Krikorian, executive director of the Center for Immigration Studies, which opposes the comprehensive reform bill passed by the Senate.“If the job is to actually deter illegal crossings, prevent people from crossing and take into custody people they catch — then they clearly don't have enough capacity.”