PORTLAND - A panel of federal judges ruled Thursday that Maine must redraw its two congressional districts to reflect population shifts in time for the 2012 elections, rather than wait until the next year.

The state’s current practice for redistricting was challenged by two Cape Elizabeth residents, William DeSena and Sandra Dunham. On March 28 — four days after Maine’s 2010 census data was released — the two sued, arguing that their votes will be diluted next year if the congressional districts aren’t redrawn to even out the populations.

The Maine Attorney General’s Office agreed that the state’s congressional districts are no longer as equal in population as required by the Constitution. The Maine Democratic Party intervened, arguing otherwise.

The census indicated that the population of the 1st Congressional District, made up of York, Cumberland, Lincoln, Sagadahoc and Knox counties and part of Kennebec County, stood at 668,515 while the 2nd District had a population of 659,848.

The panel – Judges Bruce Selya, D. Brock Hornby and George Singal — was unanimous in its decision.

After a hearing Thursday, the judges took the unusual step of announcing on the spot that they find the districts unconstitutional and that the state must redraw district lines now. They announced their decision without delay because next year’s elections are so close.

Congressional candidates can get nominating petitions starting Jan. 1. The submission deadline is March 15, and the primary is scheduled June 12.

The system that Maine has used since 1993 calls for its congressional districts, as well as its legislative districts, to be redrawn every 10 years, with the next adjustment in 2013.

A bipartisan commission submits a plan to the Legislature. If the Legislature cannot adopt a plan with two-thirds majorities, the Maine Supreme Judicial Court makes the apportionment. The court ended up settling congressional district boundaries in 1993 and 2003.

DeSena and Dunham’s lawsuit names state officials, including Gov. Paul LePage, as defendants.

At Thursday’s hearing, the plaintiffs’ lawyer, Timothy Woodcock, and Deputy Attorney General Paul Stern argued that it would be unconstitutional to go into the 2012 congressional election with districts based on outdated census data.

Woodcock said the purpose of the census is clear.

“It’s intended to allow for the fair apportionment in this most representative of our institutions,” he said.

Former Maine Attorney General Janet Mills, representing the Democratic Party, noted that census data is released at a time when the Legislature is occupied with the state budget and other contentious matters — not a good time to work on redistricting. She stressed the need to maintain a methodical, bipartisan process.

“In some of the other states, the majority party just rams something through,” she said after the ruling.

Maine and Montana are the only states that would not redistrict until after the 2012 election. Montana, however, has only one congressional district.

In a prepared statement, Maine Democratic Party Chairman Ben Grant said, “Maine has a historical tradition of working in a bipartisan fashion to redraw our congressional lines. We hope that tradition is not broken in this speedy process.”

Maine Republican Party Chairman Charles Webster said he was not surprised to see the judges rule that the lines must be redrawn before the election.

“The Constitution’s pretty clear,” he said. “I’m not a lawyer, but that’s the purpose of redistricting.”

Selya, the panel chairman, said the judges wrestled with how the situation should be resolved. He said the court must balance its responsibility for seeing that its decision is carried out with Maine’s sovereign interest in determining the procedure.

The parties in the lawsuit have until June 17 to submit proposals for how the court’s decision should be carried out. Each side will have until June 20 to comment on the other’s plan.

Selya said the judges will issue a written ruling in a couple of weeks.

The Associated Press contributed to this report. 

Staff Writer Ann S. Kim can be contacted at 791-6383 or at:

akim@pressherald.com