Through the years, "business travelers always have prided themselves on knowing the system" for airport screening, he said.
Before September 11, 2001, airport screening was provided by private companies which were contracted with the airline or airport.
The tests also are not likely to provide results fast enough to be used, say, for airport screening.
Spending on airport screening would not significantly rise, but many other divisions of the department would get new money.
But on the critical issue of airport screening, it goes further than the administration had suggested.
Security officials worry that such plastic weapons could evade detection at airport screenings.
The president's proposal for airport screening may not satisfy all parties.
For airport screening, images are taken from both sides of the human body.
But he said that the family had not given up on bringing scrutiny to airport screening.
For there it is, on the list of banned items caught in airport screenings last year: 294,694 clubs.