[TigersEye]

...they must not belong to a belief or group (Wahabbism, Communism, the Atzlanti nuts for example) that opposes what the US stands for.

Hey that's good! We simply ask everyone who comes in to the U.S. "Do you plan on subverting our laws and/or committing terrorist acts?" and if they answer "yes" we send them back. Brilliant!

Get Tom Ridge on the line and let him know what you came up with.

Now how do we get the questionaires to the ones who are sneaking in at night and in the backs of freight trucks?

[Central_Floridian]

If you were there, you could use you knowledge of what everyone has said, done, or thought to ensure that no terrorists or criminals enter the US.
If, however, you are busy applying your abilities elsewhere I suppose the INS could check the records of the country they are from, use polygraphs, or other time-tested methods.