[Bob Mc]

"You can be arrested and jailed for refusing to submit to the search once inside the airport."

To illustrate the point even further:

Try walking up to the security checkpoint with your carry on luggage. Say to the security people there something like this:

"You mean I have to let you x-ray my luggage and I have to walk through this metal detector???"

Then say, "No thanks!", and turn around and walk away.

See if they let you walk away. See if you can still refuse to consent to a search.

[Poohbah]

Then say, "No thanks!", and turn around and walk away.

See if they let you walk away.

Well, you gave anyone with an IQ greater than 3 probable cause to be suspicious of you...

See if you can still refuse to consent to a search.

Check out the case law regarding the discretion of police officers to search persons acting strangely in the immediate vicinity of a port of entry into the United States.

[RGSpincich]

To illustrate the point even further

Try walking away without attempting to bait someone who's job depends on assessing and searching people. Or better yet walk up to the sign that warns you of the impending search (usually placed at the entrance to the building), read it, go home. It's easy.