The Bush administration has until the end of today to decide whether to take a stand in a Supreme Court case pitting former Whitewater prosecutor Kenneth Starr and President Bush's brother-in-law against a coalition of evangelical Christians.

The administration is not a party to the case, in which wine producers are trying to overturn state laws prohibiting Internet wine shipments. But the White House finds itself caught between two parts of Bush's political base: business interests who favor freer commerce and religious conservatives concerned about minors buying wine.

People involved in the case said the matter was still being debated within the administration late Tuesday. A White House spokeswoman yesterday referred questions to the Justice Department, where a spokesman did not respond.

Starr, representing groups called the Coalition for Free Trade and the Family Winemakers of California, has been prominent in representing the wine industry as it fights bans in Michigan and New York of direct sales of wine across state lines, generally done via the Internet. "The laws of these states are antithetical to the principle of free interstate trade on which this nation was founded," Starr wrote in the Wall Street Journal. "With their blatant discrimination against out-of-state economic interests, these laws are constitutionally indefensible."

On Starr's side are an ad hoc group called Free the Grapes and the Wine Institute, an industry group. Robert P. Koch, who is married to President Bush's sister, Doro, is the group's president.

On the other side are New York and Michigan, who are supported by attorneys general from 35 states. (About half the states have bans on direct wine sales.) The states are joined by liquor distributors and a coalition of religious and community groups including the National Association of Evangelicals, the Eagle Forum, Concerned Women for America and American Values. These groups have joined a friend-of-the-court brief to be filed today by the Michigan Association of Secondary School Principals.

"When I saw this case I immediately jumped on it," said Richard Cizik, vice president for governmental affairs for the National Association of Evangelicals. Cizik said he will be "disappointed" if the administration does not side with him. "Underage youth are purchasing alcohol at alarming rates," he said.

Winemakers say such fears are fueled by distributors who fear lost business, but the opinion is widely held among social conservatives. "Internet sales has the real potential of making the parental job even harder," said Gary Bauer, who leads American Values. "Anything that undermines the progress that has been made on keeping underage kids away from alcohol is bad."

Supporters of direct wine shipments point to a 2003 study by the Federal Trade Commission finding that direct shipment of wine saved consumers as much as 21 percent and that states had other ways to limit sales to minors. "The rhetoric from the other side has been refuted, but they still bring up the same tired arguments," said Jeremy Benson, a spokesmen for the wine producers.

But the supporters of the Internet sales bans are not convinced. "It's virtually impossible" to block direct shippers from selling to minors, said Jim Ballard, executive director of the Michigan Association of Secondary School Principals. "We do not need to increase uncontrollable access to alcohol for underage students."

Though Starr is widely respected among Bush administration officials, the other side has hired a lawyer who is almost as admired: Miguel Estrada, who was Bush's choice to be a circuit court judge before Democrats blocked his nomination.

Kenneth Starr, former Whitewater prosecutor, represents winemakers challenging state bans on interstate sales over the Internet.