DENVER -- This year's Colorado legislative session is history, but the final hours are sure to be remembered for some time because they were so contentious and partisan.

Despite much heated debate, Senate Republicans on the last night of session passed a bill to redraw the state's congressional districts.

The district boundaries were determined by a judge less than two years ago when Republicans and Democrats couldn't agree on how and where the state's new 7th Congressional District should be drawn.

Republicans, who have a majority in the state Senate, are trying to solidify their control over that district and their tenuous hold on a new U.S. House seat, which would bolster the party's majority in Congress.

By a margin of 18-17, Republicans pushed a new congressional map through the state Senate. The bill now goes to GOP Gov. Bill Owens for a promised signature.

Each Senate Democrat voted against the bill, saying that the Republicans rammed the map down their throats at the 11th hour, and argued that the new boundaries will give the GOP an advantage in the next congressional election.

"What's going on here is a battle for the United States Congress and it has clearly come from the White House," said Senate Minority Leader Joan Fitz-Gerald, D-Golden. "They're trying to use Colorado as a test base to start to take seats away that were competitive. This is a sheer power play on their part."

Republicans say the bill wasn't introduced earlier in the session because they thought it would raise hurt feelings among their colleagues across the aisle.

Democrats said the new map is unconstitutional, and vow to fight it in court.

Republicans argue that they have the authority because the state Constitution says district lines are to be drawn by the Legislature. Leaving the court-ordered plan in place would amount to a shirking of duty, since the Legislature has never approved a plan, said Owens.

"The Constitution requires the Legislature to redistrict and this Legislature is doing that," Owens said.

The new maps would shore up Republican Rep. Bob Beauprez, who eked out a win by 121 votes to become the first Congressman to represent areas north and east of Denver in the new 7th Congressional District.

The new seat -- created because of population growth recorded in the 2000 Census -- was evenly split among Republicans, Democrats and unaffiliated voters. The GOP plan would give the party a 27,000-vote lead in registration.