AUSTIN (April 20, 2009)--David Hernandez owns several liquor stores near the Texas-Mexico border, and on any given Sunday, while he's behind the counter doing paperwork, he'll watch customers drive up.

They try the door, find it locked and then drive off toward Mexico to buy whisky or tequila.

Those sales could have been his if Texas allowed him to be open Sundays.

Now, he's fighting to repeal the state's Prohibition-era "blue law" ban on Sunday distilled liquor sales.

He says he could boost business by 15 percent by opening his Holiday Wine & Liquor stores up and down the lower Rio Grande Valley seven days a week.

The hardest fight isn't necessarily with teetotalers and social conservatives, however; it's with other liquor store owners who believe Sunday sales would barely cover the cost of staying open.

Texas allows Sunday beer and wine sales at grocery stores, and liquor may be sold in bars and restaurants.

Only liquor stores are shut out.

The statewide Sunday ban dates at least to 1935, when lawmakers wrote what is now known as the Texas Alcoholic Beverage Code at the end of Prohibition.