Acting in one of the most contentious redistricting controversies in decades, the Supreme Court today ordered a lower court to reconsider its decision upholding the 2003 Republican-drawn congressional district map for Texas.

The high court said the case should be reviewed in light of its opinion last April in a case from Pennsylvania. In that complicated ruling, the court left open the door for court challenges to redistricting based on claims of partisan gerrymandering but offered little new guidance to lower courts on how to consider such claims.

The action does not carry with it any mandate for the appeals panel to alter the outcome of the case. The three-judge federal panel that upheld the Texas map could reinstate its ruling, revise it marginally or reverse it. Reversal, analysts believe, is a long shot.

It was yet another chapter in a venomous partisan battle involving two unsuccessful walkouts by Texas Democratic lawmakers and an ethics infraction by Majority Leader Tom DeLay (R-Tex.). In an unprecedented mid-decade redistricting of Texas, Republican lawmakers redrew the map so as to give Republicans a 10- or 11-member edge in the state's 32 member congressional delegation, which is now split evenly.

DeLay, a 10-term veteran, helped engineer the redistricting, and asked the Federal Aviation Administration to help locate a plane that Republicans thought was carrying Texas Democratic legislators who had left the state to prevent a quorum that Republicans needed to pass the new map.

On Oct. 6, the House ethics committee admonished DeLay for his role, citing a rule that bars members from taking "any official action on the basis of the partisan affiliation . . . of the individuals involved."

The Texas map has been challenged in more than half a dozen cases by Democrats and minority groups. They have argued, among other things, that it was unconstitutional partisan gerrymandering, a violation of voting rights laws and an impermissible departure from a tradition of redrawing districts once every 10 years.

Paul Smith, who represents a group of challengers, said in an interview that today's action suggests, at least, that the court "thought there was a serious issue" raised in the Texas cases.