A fight is brewing between the Bush administration and state governments over post-9/11 security rules for driver's licenses.
Stuck in the middle are residents of at least 17 states. They may find themselves unable to use their licenses to board planes or enter federal buildings.
Homeland Security Secretary Michael Chertoff says if states want their licenses to remain valid for air travel after May, they have to seek a waiver for more time to comply with the new rules put in place by what's known as the REAL ID Act.
Without such a waiver, Chertoff says residents would have to use a passport or a newly-created federal passport card to avoid a secondary screening at airport security.
Many of the states objecting to the REAL ID provisions say it will cost too much to comply.