June 7 (Bloomberg) -- The U.S. Supreme Court refused to reinstate Colorado congressional districts redrawn by Republican lawmakers last year after they gained control of all three branches of state government.

The justices declined to second-guess the Colorado Supreme Court's decision throwing out the new map on grounds the state constitution allows only one redistricting after each census. Today's action leaves in place a congressional map drawn in 2001 by a court after the legislature, at the time split between Democratic and Republican control, couldn't agree on a plan.

Colorado and Texas are embroiled in legal fights over congressional districts adopted last year by new Republican legislative majorities seeking to boost their party's lead in the U.S. House of Representatives. With elections this November, Republicans hold 228 House seats and Democrats have 205 with one independent and one vacancy.

``It is the state legislature -- not any other part of the state -- that has the delegated power to establish the rules governing federal elections'' based on the U.S. Constitution, lawyers for the Colorado legislature said in court papers filed in Washington.

Republicans hold five of Colorado 's seven congressional seats, and Democrats say the map created last year would have bolstered Republicans' hold on those five seats.

In a separate redistricting dispute, the Supreme Court in April upheld Pennsylvania 's congressional map, ruling 5-4 against a Democratic appeal that claimed the Republican-created districts were so partisan they violated the Constitution's guarantee of equal protection under the law.

`Once Per Census'

Lawyers on both sides of the Colorado case said the issue involved in the Pennsylvania decision wasn't raised in the Colorado dispute.

In Colorado , Republicans took control of the state Senate from the Democrats in the November 2002 election, putting both houses of the legislature and the governorship in the Republican column. Lawmakers enacted the new congressional districts last year to replace a judge-drawn map from 2001.

State Attorney General Ken Salazar, a Democrat, sued in the Colorado Supreme Court to challenge the new districts. The court ruled in his favor, saying the state constitution ``limits redistricting to once per census,'' whether the districts were created by the legislature or a court.

``Having failed to redistrict when it should have, the General Assembly has lost its chance to redistrict until after the 2010 federal census,'' the state court said.

`Political Instability'

In appealing to the Supreme Court, the General Assembly argued that the U.S. Constitution delegates the power to control federal elections to state legislatures, not state courts. Court- drawn districts should exist only temporarily until the legislature acts, the appeal said.

Salazar said the state court ruling was based on the state constitution and had no effect outside Colorado . Upholding the General Assembly's argument ``would likely lead to undesirable political instability in Colorado through repetitive redistricting,'' he said.

The Supreme Court hasn't yet acted on an appeal by Texas Democrats challenging that state's new districts drawn by Republicans last year. As in Colorado , the new map was intended to replace one created by a court based on 2000 census results after a legislative deadlock.

The Texas appeal argues that only one redistricting is allowed in the state after each census, and that the new plan is unfair to black and Hispanic voters. Democrats have a 17-15 edge in the Texas delegation, and the new districts would make it easier to elect Republicans to 22 of the seats. A three-judge federal court upheld the districts in January.

The Colorado case is Colorado General Assembly v. Salazar, 03- 1082.