(WSJ) - Wal-Mart Stores Inc. was slow to get into alcohol, but now it is fighting for the right to sell more of it.

A prime target is Texas, where the world’s largest retailer has sued the Texas Alcoholic Beverage Commission, saying legal limits on sales of hard liquor are unconstitutional.

One restriction prevents public companies—those with more than 35 shareholders—from selling spirits. The state beverage code also says no company can own more than five liquor stores unless permits for the others are bought from a blood relative.

In addition to filing a lawsuit, Wal-Mart has joined Kroger Co., Costco Wholesale Corp. and other groups in backing legislation that would override the laws, which date back decades.

“Texas is the only state in the nation that allows private companies to own liquor stores while prohibiting public companies from doing so,” said Travis Thomas, a principal at the Monument Group, an Austin, Texas, communications consulting firm hired by the retailers.

The showdown—and others like it around the country—pit big retailers desperate to draw more traffic into their stores against smaller incumbents in the lucrative liquor trade that often are protected by idiosyncratic laws.

Wal-Mart, based in Bentonville, Ark., is supporting legislative efforts to make it easier to sell alcohol in several states. Texas is a linchpin of the effort. The state is home to around 560 Walmart and Sam’s Club stores—more than any other state in the country—and Wal-Mart is hoping to open stand-alone liquor stores adjacent to its locations as well. Another Texas law states that spirits can’t be sold in the same store as groceries.

Several retailers are focused on boosting their alcohol sales. Alcohol is generally more profitable than other consumer goods. And, at a time when chains are facing tough competition from the Web, alcohol draws shoppers into stores. In industry parlance, liquor is a “trip driver.”

Alcohol is also something shoppers will splurge on. “Not everyone is trying to spend as little as possible,” said Matt Tullman, co-founder and chief executive of Merchant Mechanics, a West Lebanon, N.H., consumer-research consulting firm.

The move to sell more alcohol, including in stand-alone liquor stores, is a significant shift for Wal-Mart. It is part of a broad effort to boost U.S. sales that rose a slim 0.5% last year, excluding newly opened stores. Wal-Mart is also pouring money into its e-commerce business and is focused on building smaller format Neighborhood Markets. The company is trying to boost its grocery business generally, working to improve the quality of the produce and meat it sells.