U. S. President Barack Obama, members of Congress and just about everyone else describe what's happening at the U.S. border with Mexico as a "humanitarian crisis," but that's where the consensus ends.

The problem of what to do about the flood of unaccompanied children and other migrants from Central America who are coming across the border in record numbers is dominating the agenda in Washington so far this summer and deepening the division that was already paralyzing Capitol Hill.

Here's an overview of the story.

What exactly is the 'crisis?'

The number of unaccompanied minors has exploded in the last year. Just since October, more than 52,000 children have made their way across the U.S.-Mexico border without their parents. Most of them are from El Salvador, Guatemala and Honduras. They make treacherous journeys, some riding atop freight trains, and in some cases their parents have paid smugglers to get them to the U.S. Not all of them survive the trip. Recently the decomposing body of an 11-year-old boy was found in bushes not far from the border. Another 39,000 adults with children in tow have also arrived in recent months. The bulk of the migrants are arriving in the Rio Grande Valley in Texas where they are apprehended and handed over to U.S. Border Patrol. Border patrol guards are being stretched to the max, detention facilities are overflowing and the backlog to process the migrants, which was already big, is ballooning.  

Why are they coming?

Because conditions in Honduras, El Salvador and Guatemala are frighteningly bad. These countries top the list of worldwide murder rates. Youth are forced into gang activity, and threatened with death if they resist. Some parents feel there is no choice but to send their children out of the country to escape the violence. They are trying to get them to a relative already in the U.S. and if there isn't one, they know the children will be given food, shelter, and medical care. That's a better alternative to conditions back home, even if it is temporary and they are eventually sent back. Smugglers are also blamed for spreading misinformation about U.S. immigration, telling vulnerable parents that they children will be welcomed with open arms and automatically allowed to stay. 

Immigration Obama

In this June 20, 2014 file photo, immigrants who entered the U.S. illegally stand in line for tickets at the bus station after they were released from a U.S. Customs and Border Protection processing facility in McAllen, Texas. (Eric Gay/Associated Press)

What happens once the children get across the border?

The Department of Homeland Security transfers unaccompanied minors to the Department of Health and Human Services within 72 hours. The children are placed in shelters. The demand for these shelters is now outstripping the supply. The minors are given medical exams, vaccinations if necessary, and are interviewed to determine if they were victims of trafficking or other crimes. They have access to counselling and legal services. Most of the children are released from the shelters into the custody of a relative or guardian once arrangements are made. Then they wait for their case to work its way through the backlogged immigration and deportation systems. Some lawmakers have questioned authorities about how many actually show up for hearings and they're having trouble getting answers. If the child has no relative in the U.S., they stay in a shelter.  

OK, so it’s a big problem. What’s being done about it?

Some of the response measures include the following: Federal agencies have expanded their capacities to process and house the children, moving some from Texas to facilities in Arizona, California and Oklahoma. Spanish-speaking case management staff have been increased and more border guards were dispatched to Texas. On the diplomatic level, Vice President Joe Biden travelled to Guatemala and other top officials have been engaged with regional leaders to try to address the root causes and co-ordinate their responses. 

Immigration Overload

U.S. Customs and Border Protection agents work at a processing facility in Brownsville, Texas, on June 18, 2014. (Eric Gay/Associated Press)

The U.S. has committed millions of dollars in aid to the source countries to improve their security and economic conditions and to help repatriate their returned citizens. Public awareness campaigns are running in El Salvador, Guatemala and Honduras warning parents not to believe what smugglers tell them and about the dangers of sending their children on dangerous and potentially deadly trips.

That all sounds like it could cost a lot of money. What’s the price tag?

Obama on Tuesday asked Congress to approve $3.7 billion US in additional funding to deal with the crisis. He may not get the approval he needs. Republicans blame Obama for the whole mess in the first place, saying he’s been lax on enforcing immigration laws and that's encouraged the flood of migrants. They say they don't want to give him a blank cheque and want to see some policy changes, not just measures to respond to the immediate crisis. Some of the requested money would go to expanding the detention and shelter facilities, increasing aerial surveillance at the border, and hiring more immigration judges in an effort to more quickly remove those who aren’t granted asylum.

Some lawmakers suggest the children should just be put on planes and sent right back to where they came from – why doesn't the U.S. do that?

Because these migrants aren't Canadian or Mexican. If they were, they'd likely be turned right around the same day but back in 2008, President George W. Bush signed a law, passed by Congress with bipartisan support, that says when people from countries such as Honduras, El Salvador and Guatemala cross the border, they are to be given legal protections. The law was aimed at cracking down on human smuggling and yes, now some on Capitol Hill are saying it should be changed.

The administration says it is enforcing the law and giving due process to the migrants. Children or not, they will be sent home if it's determined by a judge that they have no legal basis to stay, the White House says. Obama has said that in "most cases" the legal process will result in the children being sent home and that he’s sending a message to parents not to put their children at risk. Whether they will listen or not will be borne out in the months to come.