Tested in Russia, the two-stage GK-1 voice analyzer requires that passengers don headphones at a console and answer "yes" or "no" into a microphone to questions about whether they are planning something illicit.
So if a politician wants to board, just find out where he's from and ask him if he really intends to abide by his oath of office.
Maybe we can hook gun owners up to one as part of the background check, and ask 'em if their thoughts are loyal and pure...