They signed up to fight for their country, and the state of Texas promised to pay for their education.

For decades, Texas — which has the state second-highest veterans' population in the country — has funded higher education for the enlisted under the Hazlewood Exemption.

But in 2009, Texas lawmakers passed a legacy provision that allows veterans to pass the benefit onto a child. Since then, costs have increased sevenfold, from $25 million to $169 million last fiscal year.

That rise, along with concern that a federal lawsuit over residency could push the benefit's annual price tag to $2 billion, has lawmakers trying to balance politics and fiscal conservatism with commitments made to veterans long ago.