Washington ? The Supreme Court agreed Monday to hear a constitutional challenge to the hotly disputed Texas redistricting plan engineered by former House Majority Leader Tom DeLay, R-Texas, in 2003 that handed Republicans six extra seats in the U.S. House of Representatives.

In a surprise move, the court said it would consider reining in the most extreme forms of partisan gerrymandering. The Supreme Court previously has rejected such challenges, concluding it is impossible to separate partisan politics from the drawing of electoral districts.

But the Texas case stands out because Republicans pushed through the redistricting as soon as they gained control of both houses of the state legislature – just two years after a different redistricting plan based on the latest census, the traditional yardstick, had been approved by the courts.

The challengers call it a “purely partisan” move that violated the Constitution because it deprived Democrats of a fair and equal chance to elect representatives of their choice. They say the new congressional boundaries diluted the voting power of blacks and Latinos by shifting them into different districts.

The justices said they will take up the legal challenge brought by Democrats and minority voters in the spring and rule by the end of June.

The court’s move to hear the Texas case could spell trouble for the Republicans, who have controlled the House for a decade. If the justices were to strike down DeLay’s plan as unconstitutional, it could force political boundary changes in time for the 2006 congressional elections.