Updated

The Bush administration faces a touchy political choice over whether to join a Supreme Court showdown on affirmative action, a case that is a lightning rod both for conservatives and for minority voters the Republicans are courting.

The high court is expected to rule later this year on the constitutionality of programs that gave black and Hispanic students an edge when applying to the University of Michigan and its law school.

The ruling would be the court's most important statement on racial preferences in a generation and could substantially change the way public colleges and universities select their students.

The administration is not a party to the Michigan fight and does not have to take any position. Traditionally, however, the White House weighs in on potentially landmark cases.

The administration has not said whether it will intervene, but must make that decision soon. Legal briefs opposing affirmative action are due to the court Jan. 16, and briefs supporting the Michigan admissions plans are due in February.

"It is a really difficult position for them," said Eric Schnapper, a University of Washington law professor. "It really is an important decision about the future of the Republican Party."

Further complicating the White House's decision is the continued fallout for the GOP from the racially provocative comments that cost Sen. Trent Lott, R-Miss., his job as Senate majority leader. Bush strongly condemned Lott's remarks, which were widely interpreted as nostalgia for segregation.

Siding with white students so soon after the Lott controversy could be seen as an affront to blacks.

"Obviously there's a political sensitivity to this that has been enhanced," said Theodore Shaw, associate director of the National Association for the Advancement of Colored People Legal Defense and Educational Fund.

Affirmative action supporters point to California as a cautionary tale. Battles over illegal immigration, affirmative action and bilingual education that raged through most of the 1990s under then-GOP Gov. Pete Wilson left many Hispanics suspicious and angry toward Republicans.

Politics muddies a legal and constitutional issue that is quite stark, lawyers said. The Michigan case reopens the fundamental question of whether race or ethnicity can ever be a factor when public universities decide whom to accept.

Conservative purists, who tend to vote Republican, say racial preferences violate the Constitution's guarantee of equal protection for all. Supporters of affirmative action, many of them Democrats, say preferences are justified by past discrimination and that the Constitution does not forbid them.

Both sides predicted the administration will side with them if it takes a position at all.

"I think there will be a strong brief and that it will argue that a desire for prefab diversity does not justify racial and ethnic discrimination," said Roger Clegg, general counsel of the Center for Equal Opportunity, which opposes affirmative action.

Clegg and other conservatives take heart in Bush's stated antipathy for racial quota programs, and in the past positions of Attorney General John Ashcroft and Theodore Olson, the administration's top Supreme Court lawyer.

"I hope they are aware that there are practical and political consequences," countered Shirley Wilcher, executive director of the pro-affirmative action Americans for a Fair Chance.

Backing white students who claim they were wrongly excluded from Michigan because of their race "would not send the signal of compassionate conservatism that (Bush) propounds," Wilcher said.

A dozen organizations sent Bush a letter this week urging him to endorse the Michigan admissions programs and noting that 11 percent of Hispanics in the United States have college degrees. Among non-Hispanic whites the figure is 28 percent.

Hispanics are the fastest-growing minority group, and Bush has tried to draw Latino voters to the Republican Party.

With one constituency or another sure to resent the White House position, the administration may choose to sit out the Michigan fight, lawyers on both sides said.

"It will be awkward for them not to file a brief, but they may conclude that politically it is the least bad option," Clegg said.

Both sides said they would prefer silence to White House opposition.