A person with good personal hygiene.
A well-dressed gentleman.
One with multiple forms of valid identification.
And who is obviously well-educated.
A person with a clean police record.
Impeccable references available on request.
A law enforcement officer.
Not just any ordinary officer though - a Secret Service agent.
An agent who has personally guarded the President of the United States.
Oh... He's of Arab descent. Don't bother checking his references... just kick him off the plane.