HARLINGEN, Texas -- In a storefront courthouse in the baking-hot Rio Grande Valley, next to a ''beauty academy" and across from a sleepy coffee shop, US Immigration Judge David Ayala is a study in effortless efficiency. He pulls blue files one by one from a tall stack, announces the name of an undocumented immigrant caught slipping across the US border, and orders the defendant deported.
There are no cries of protest. The defendants are nowhere to be found. Other than the thwack of a stamp and the judge's voice, the only other sound in the tiny courtroom is the quiet hum of an air conditioner, as Ayala goes through the motions before a Department of Homeland Security prosecutor and a reporter.
Unlike undocumented Mexicans, most of whom are quickly returned to their country after they are arrested, almost all non-Mexicans are charged and released in the United States if they do not have a criminal record and are not deemed a security threat. But like this day, few of the immigrants show up to face charges that they entered the country illegally.
When their names are called, 98 percent of all undocumented aliens ordered to appear at Harlingen Immigration Court do not answer. They are weeks into their new lives in all corners of the United States.
The no-show rate, the highest of those for all 53 immigration courts in the country, has deteriorated as undocumented, non-Mexican immigrants have been crossing the border in exponentially increasing numbers, many from known terrorist breeding grounds such as Pakistan.
High-ranking federal officials, including retired Admiral James Loy of the Coast Guard, who served as deputy secretary of Homeland Security until March, have warned Congress that terrorists might exploit the porous border with Mexico to enter the United States, where they can take their chances with immigration officials who often have no choice but to release non-Mexicans.
Such infiltration ''is a concern for us," said Roy Cervantes, the US Border Patrol spokesman in Harlingen.
Nationwide, the number of non-Mexicans who are entering the country illegally is skyrocketing, according to the Department of Homeland Security. Through Aug. 9, for the first 10 months of fiscal 2005, a total of 135,097 non-Mexicans had been apprehended out of 1.02 million undocumented immigrants arrested overall. In all of fiscal 2004, the number of non-Mexicans apprehended was 75,392; in fiscal 2003, the figure was 49,545.
The arrivals are coming from all over the globe, using smugglers in Mexico and the United States to ferry them to river crossings and to guide them along dangerous desert trails in their quest for a better life. The inability of the Border Patrol to stem the tide has provoked a fierce debate about immigration policy and security priorities. The governors of New Mexico, Bill Richardson, and of Arizona, Janet Napolitano, both Democrats, declared states of emergency along their southern borders this month.
Big-business interests are concerned that an aggressive federal crackdown on immigration could affect the estimated 10 million undocumented workers in the United States, and who provide a steady source of low-cost labor.
But many lawmakers from border states and others, such as the Minutemen volunteers who monitor the borders, are sounding an alarm.
''The borders are worse today than they have ever been," said US Representative John Culberson, a Houston Republican who has filed a bill to create an armed volunteer militia that would be supervised by border-state governors. ''There's an absolute invasion going on."
Other observers, such as the executive director of the League of United Latin American Citizens, Brent Wilkes, suggest that the outcry against the growing influx of non-Mexican immigrants, many of them from Central and South America, is rooted in racial bias.
''We get concerned when we feel like the security issue is used as a ruse to crack down on Hispanic immigrants who are economic refugees," Wilkes said. ''There's a lot of people playing up the threat of terrorists coming across the Mexican border."
Immigration officials say they are doing the best they can with what they have. But if they do not release most non-Mexican immigrants, federal officials say, the alternative is to detain tens of thousands of them in a time-consuming deportation process whose difficulties are compounded by a shortage of detention space. With 19,500 beds nationwide all filled, the result ''forces us to make some very difficult decisions," said Dean Boyd, a spokesman for Immigration and Customs Enforcement for the Department of Homeland Security.
Nowhere are those decisions more evident than in Harlingen. In the first nine months of fiscal 2005, which ends on Sept. 30, 16,376 undocumented immigrants failed to appear at court. Only 214 of them were Mexican. In fiscal 2004, 9,166 immigrants did not appear, or 88 percent. In fiscal 2003, the no-show number was 4,868, again a national high at 88 percent.
In the sprawling Rio Grande sector, which includes Harlingen and covers 320 miles of the river, 68,438 non-Mexican immigrants from 65 countries have been arrested this fiscal year, Cervantes said. That number amounts to much more than double the 26,437 non-Mexican immigrants who had crossed illegally into this sector for all of fiscal 2004.
In the border city of Brownsville, 25 miles downriver from Harlingen, the Border Patrol chief, Ernesto Castillo, said the 202 agents in his busy station are insufficient to do the job. The agents from Brownsville are averaging about 60 arrests a day, Castillo said, including three whom he watched being detained recently on a patrol of the levee along the Rio Grande.
Two of the immigrants, a married Mexican couple who spoke no English, clutched each other as agents tended to a deep, bloody wound that the 24-year-old woman had suffered by falling in a drainage ditch. The two were returned to Mexico later that day.
Nationwide, the failure-to-appear rate for fiscal 2005 stood at 36 percent on June 30, or 68,634 of the undocumented immigrants who had been arrested.
In fiscal 2004, the 54,261 suspects who did not appear in court included 530 from Pakistan, 206 from Iran, 164 from Jordan, 93 from Iraq, 80 from Yemen, and 29 from Afghanistan, according to Justice Department figures.
Boyd said that undocumented aliens from a ''special-interest" country, a term the government uses to describe a potential base for terrorists, undergo careful screening and are not released until investigators are confident they do not pose a security threat. ''Because someone comes from Pakistan, that doesn't necessarily mean anything," Boyd said. ''It could be a family with children."
However, the numbers of illegal immigrants from such countries are raising questions about the adequacy and consistency of US border protection. ''I think there's a lack of urgency about this in the White House and Congress," said Mark Krikorian, executive director of the Center for Immigration Studies, a nonpartisan think tank based in Washington. ''This has the potential to be a really big deal, and there's going to be political hell to pay."
Culberson, the Houston Republican, went further. ''Any day now, we will confront massive truck-bomb explosions in our major cities and catastrophic loss of life inflicted by Middle Eastern terrorists who will laugh at us that they had simply walked across our border and we let them do it," he said.
Under Culberson's plan, which has 50 cosponsors in the House, volunteers from anywhere in the country could join a state's Border Protection Corps and ''use any means and any force authorized by state law to prevent" illegal immigration. Corps members would be subject to background checks for criminal history and mental illness, he said.
Wilkes, of United Latin American Citizens, bitterly criticized the proposal. ''If you give these people any means necessary to make arrests, when the crime the immigrants is committing is a misdemeanor, it's outrageous; it's sick," Wilkes said.
Border Patrol officials, meanwhile, pointed to a recently implemented program, called ''expedited removal," as a success story. Begun in 2004 in Tucson and in Laredo, Texas, the program was expanded in July to target a huge increase in undocumented Brazilians crossing the lower Rio Grande Valley. As a result, Cervantes said, the flow of Brazilians, who had become the largest non-Mexican group entering the area, has been dramatically curbed.
To qualify for ''expedited removal," an undocumented immigrant must not have a criminal past, must not be a juvenile, must not be an asylum seeker, and must have been arrested within 100 miles of the border and 14 days since crossing the boundary, according to Salvador Zamora of US Customs and Border Protection, an arm of the Homeland Security Department.
Since July, 757 Brazilians have been flown back to their country at US expense, the Border Patrol said. Zamora added that the hope is eventually to extend ''expedited removal" along the entire southwestern border.
Meanwhile, the ebb and flow of the immigration battle is evident at the Border Patrol station here, where most of the undocumented, non-Mexican aliens are released to the street after being questioned and given a court notice.
Once outside the station's chain-link fence, many of the immigrants board a shuttle sent from the Harlingen bus station, where they depart for destinations throughout the country, Cervantes said.
''They've been constantly here," said Jose Degollado, who works at the bus depot.
In Brownsville, Castillo shook his head when asked if he had become frustrated by the no-show rate at court. ''Our job," he said, ''is to apply the law."