Immigration and Customs Enforcement (ICE) has released several hundred unauthorized immigrants from detention in Texas, Florida, Arizona, and Louisiana in preparation for budget cuts as part of the sequestration. The administration has noted that cuts would effectively reduce Border Patrol by about 5,000 agents—down to about 2007 levels of staffing if all of the cuts occur on the Southwest border. 

This reduction in Border Patrol will not unleash a tidal wave of unauthorized immigrants like many claim. Since 1989 the Border Patrol’s appropriations have increased by 750 percent and there are six times more staff today than in 1989. 

Apprehensions of unauthorized immigrants on the border are also near 40 year lows because fewer unauthorized immigrants are trying to enter illegally due to the poor economy. Decreasing the size of the Border Patrol will not do much to increase unauthorized immigration because many would-be immigrants are repelled by high unemployment rates.  

Unauthorized immigration has slowed dramatically because of a lack of economic opportunity in the United States, not because border patrol is larger or more effective. Cuts to Border Patrol, even those that would return its size to the 2007 levels, will not much affect unauthorized immigration.

American unemployment rates and demand for immigrant workers drive unauthorized immigration.  Look at this graph relating border apprehensions and the national unemployment rate:

The higher the rate of unemployment, the fewer unauthorized immigrants try to enter, and the fewer apprehensions are made.   

Perhaps if you had looked at this graph, you might have thought that the size of the Border Patrol could deter unauthorized immigration:

But if Border Patrol deterred unauthorized immigration, it would probably also deter other illegal activity—like cross border drug seizures. Consider this graph:

Drug seizures have increased along with the size of the Border Patrol. Americans still demand marijuana so increased security results in more marijuana seizures (and more marijuana entering the black market). In contrast, unauthorized immigration is down because there is less American economic demand for their labor. Decreasing the size of the Border Patrol down to 2007 levels will not result in a flood of unauthorized immigration because not as many people want to come here as they did during the housing boom.