Steven Kelman, professor of public management at Harvard's Kennedy School of Government, said the eight-month rush to meet a congressional deadline was probably one of the biggest mobilizations of a civilian government agency in history.
Robert Johnson, spokesman for the Transportation Security Administration, compares the massive effort to processing troops for World War II.
"This was an enormous task, and one that people said couldn't be achieved," Johnson said. "The deadline will be met."
Not everyone is impressed. Rep. Harold Rogers, R-Ky., chairman of the House Appropriations transportation subcommittee, sees the TSA as a bloated agency with far more airport screeners than needed.
Rogers cited two examples. Each screener at Kentucky Bluegrass Airport in Lexington, which he uses on flights home from Washington, checks only four passengers an hour on average.
It's worse at Groton/New London Airport in Connecticut, he said, where a screener checks an average of one passenger every four hours.
For security reasons, Rogers can't say how many screeners are posted at each airport, but he can reveal the ratios of passengers to screeners and to what he calls "a standing army of staff."
"It's wasteful," he said. "Anybody that travels knows that we have excessive screeners out there."
TSA's Johnson said the staff should level off. Some screeners are being trained on the job, he said. Others are awaiting the arrival of the explosives-detection equipment they'll operate.
"Flying is safer today than it's ever been because of the new screener workforce," he said.
A federal judge in Los Angeles temporarily blocked as unconstitutional a new rule mandating the screeners must be American citizens.
The ruling issued Friday by U.S. District Judge Robert Takasugi will affect as many as 8,000 airport screeners, most of whom already have lost their jobs, said Ben Wizner, a lawyer for the American Civil Liberties Union of Southern California, which brought the case.
A Justice Department lawyer, Elizabeth Shapiro, declined to comment and said it was not clear the injunction would apply nationwide.
The first TSA screeners went on duty April 30 at Baltimore-Washington International Airport, and their ranks have slowly grown elsewhere.
For years, airport passenger screening was handled by private companies hired by the airlines and supervised by the Federal Aviation Administration. Most screeners earned little more than minimum wage with few benefits, and turnover was high.
After the Sept. 11 attacks, Congress ordered the federal government to take over the screening duties and set a deadline of Nov. 19 for workers to be in place at 424 commercial airports.
Five other airports - San Francisco, Kansas City, Rochester, N.Y; Tupelo, Miss.; and Jackson Hole, Wyo. - will continue to use private companies under government supervision as part of a three-year pilot program.
"The meeting of that deadline has cost a lot of money that it should not have," Rogers said. By rushing toward the deadline, the TSA neglected efficiency and cost control, he said.
The TSA had only 13 employees in January but began hiring at a rapid pace in the summer. As recently as a few weeks ago, there was considerable doubt the deadline would be met.
"It was almost a Herculean task and they really ought to be given lots of plaudits," said David Stempler, president of the Air Travelers Association.
The federal screeners have cost at least $2 billion this year. Contracts for more than $500 million went to hiring and training screeners; $320 million went to reconfigure airport checkpoints so passengers can pass through quickly.
The TSA also assumed contracts from private screening companies worth at least $1.6 billion and requested $2.1 billion for screener salaries next year.
Rogers was a leader in the effort by House Republicans to limit the size of the TSA. Congress imposed a 45,000-person cap, but the agency got around it by giving people five-year, "temporary full-time" contracts.
Starting salaries range between $23,600 and $35,400, and benefits include health care, life insurance, paid vacation and sick leave. The screeners receive 44 hours of classroom training, 60 hours of on-the-job training and a promise of advancement if they do well.
Ed Karabinus, 56, was a security manager at Shepard Air Force Base in Texas last winter when he traveled through Dallas-Fort Worth International Airport and encountered inefficient screeners who didn't speak English.
He decided to become a screener himself. He took the test, and in March he was one of 61 people hired as supervisors.
Eight months later, he has been promoted to federal security director, a new category of federal law enforcement officer, overseeing both Wichita Falls Municipal Airport in Texas and nearby Lawton Municipal Airport in Oklahoma.
Federal security directors earn between $108,400 and $150,000 a year.
Karabinus, who now drives a used Mercedes, motivates his screeners by saying, "Look where I went, guys, in eight months."