Ed Coile and his husband are true-blue Democrats. But they were thinking about saving money, not their congressional representation, when they decided to move from Washington to conservative Frederick County last year.

"Politics just didn't play a role," said Coile, 52, after getting off the commuter train at the tiny red-brick MARC station in Western Maryland on the Virginia border. "This is where we could afford to buy a house."

Democratic strategists in this part of the state, however, are thinking an awful lot about transplants from the Washington area such as Coile and husband Barry Stampler.

The strategists see them as part of a steady northbound population migration that will color this part of the state more Democratic over time. They want to radically redraw Maryland's congressional map to transform the 6th District, which has sent conservative Republican Rep. Roscoe G. Bartlett to Washington for 10 terms, into a toss-up.

Or, in the words of Frederick County Democratic Chairwoman Myrna R. Whitworth, testifying at a recent redistricting hearing: "My job is to turn Frederick blue."

Conversations about maps will intensify over the next two months as Maryland politicians turn their attention to congressional redistricting, the once-a-decade process of adjusting political borders to accommodate changes in the state's population.

A five-member panel appointed by Democratic Gov. Martin O'Malley is crisscrossing the state to hear opinions about redistricting. The panel, which includes state Senate President Thomas V. Mike Miller and House Speaker Michael E. Busch — both Democrats — is charged with recommending a map to O'Malley.

O'Malley could submit that plan or a map of his own to the General Assembly, which will meet in special session this fall to approve new districts.

The 9 percent growth recorded in Maryland in the 2010 Census means the state will retain its eight seats in the House of Representatives. But that doesn't mean the Maryland delegation will remain static: Redrawing the borders could give the state's majority Democrats a chance to unseat one of the two Republicans — or at least make their re-election much more difficult.

Rep. Steny H. Hoyer, the No. 2 Democrat in the House, has hinted that freshman Rep. Andy Harris, the Baltimore County Republican who represents the 1st Congressional District, would be the target.

Adding Democrats to the district could give former Rep. Frank M. Kratovil Jr. a shot at taking back the seat he held from 2009 to 2011. Kratovil has said he would consider the shape of the district in deciding whether to run again.

But after a series of redistricting meetings, it is clear that there is no consensus on that idea. Leaders in Prince George's County, a rich potential source of Democratic voters, have made it clear that they don't want to be part of the 1st District, which now is made up of the Eastern Shore and parts of Baltimore, Anne Arundel and Harford counties.

Western Maryland Democrats, meanwhile, want the mapmakers to target Bartlett.

The Cook Political Report, a nonpartisan newsletter that tracks congressional and other elections, gives Maryland a 50-50 chance of drawing a new Democratic seat in the House.

Maryland is one of the few states nationwide in which Democrats have the power this year to redraw congressional districts in their favor. Republicans control the process in 18 states. Democrats oversee it in six. Others are either divided between the parties or use a nonpartisan commission.

With Republicans here largely sidelined — one of the five panel members is a former GOP lawmaker — the real argument in Maryland is between different segments of the Democratic Party.

At first blush, Western Maryland isn't an obvious place for Democrats to seek inroads.

The 6th District, made up of Allegany, Carroll, Frederick, Garrett and Washington counties plus parts of Baltimore, Harford and Montgomery counties, has been the most reliably Republican district in the state over the past two decades.

Even in years that were difficult for GOP candidates elsewhere, Bartlett, a member of the House Tea Party Caucus, has routinely won re-election by 20-point margins.

But Bartlett, 85, is a lackluster fundraiser, which has led some Democrats to argue that he would not have the means to introduce himself to a new group of voters should his district take a different shape.

Helping to fuel their optimism is the victory last fall by Democrat Ronald N. Young, a former Frederick mayor, over conservative Republican state Sen. Alex Mooney in Frederick and Washington counties.

Democratic Party strategists say the influx of 48,000 transplants from the capital area over the past decade is leading fast-growing Frederick County to tilt toward the politically liberal Washington suburbs.

About one-third of the 131,000 people who moved to Frederick County in the past 10 years came from Montgomery County, according to Internal Revenue Service data.

The MARC's Brunswick line, which runs from Washington's Union Station to Martinsburg, W.Va., has seen a 34 percent increase in train ridership in the past decade, and there are roughly 10,000 more cars per day on Interstate 270 than 10 years ago.

Nowhere is the growth more apparent than in the rolling developments in Urbana, the first exit off I-270 in Frederick County.

Ten years ago, local Realtor Mary Richeimer said, the community was "a tiny crossroads." Then a developer turned a stretch of corn and soy fields into The Villages of Urbana, a 3,000-unit planned community that includes hiking trails, tennis courts, two pools, a library and a shopping strip with a grocery store.

It's not the only one. Half an hour down the road is Brunswick Crossing, another gleaming development sprouting out of farmland.

"The county's population has changed so much," said Boyce Rensberger, a Democratic activist who spoke at the redistricting meeting.

The picture is disputed by Republicans, including the one who represents the district.

"I have a very rural, agricultural district," Bartlett said in a recent interview. "It has nothing to do with the suburbs of Washington. … Small towns, volunteer fire companies."

Bartlett said redrawing his district to take away the Central Maryland portion and include more of Montgomery County would be "crazy."

"What in the heck relationship does Garrett County have to the Washington suburbs?" he said. "Or Allegany County or Washington County?"

One person who could benefit from a more Democratic 6th District is state Sen. Robert J. Garagiola, a Miller favorite who represents northern Montgomery County.

Garagiola said he's "watching closely" how the congressional district is being redrawn as he decides whether to challenge Bartlett.

"I would not run for the sake of running," Garagiola said. "If I ran, it would be to win."

A glance at the spaghetti-like tangle of congressional lines in Central Maryland shows that the state's Democratic mapmakers haven't minded cutting through communities to consolidate political power. And the Republican Party will have little voice in the process.

The current districts were drawn 10 years ago under then-Gov. Parris N. Glendening. He said in a recent interview that he was guided by two objectives: Keep the four influential Democrats from Maryland who were in office at the time and add more.

"There is no way to describe them other than political goals," Glendening said. "Redistricting, by definition, involves partisan politics."

He asked for a map that would flip two of the four seats held by Republicans from red to blue.

The "real challenge," said Glendening, was persuading the Democratic incumbents to accept districts that would be slightly more difficult to hold — a necessary sacrifice to make the Republican districts more winnable.

"They were used to winning 70 percent of the vote and still wanted that," Glendening said. "We had to sit down with them and say, 'In order for [then-Baltimore County Executive C.A. Dutch Ruppersberger] to have a real running shot, you need to give up some of these areas.'"

In the end, Glendening's map did what he wanted. Ruppersberger beat Republican former Rep. Helen Delich Bentley in 2002 to win the district held until then by GOP Rep. Robert L. Ehrlich Jr., and Democratic state Sen. Chris Van Hollen beat Republican Rep. Constance A. Morella to give the Democrats six of the state's eight House seats.

Glendening had considered a plan to make Western Maryland more Democratic by pulling the district down into Montgomery County. But he decided against it, in part because it would have been difficult to draw without disrupting every other congressional district.

And that will be the challenge for mapmakers now: Reshaping the district would upset the delicate balance that has kept at least six Maryland Democrats in the House for each Congress of the past decade.

Altering the 1st District does not trigger the same domino effect in the rest of the state.

Raquel Guillory, a spokeswoman for O'Malley, said the governor is waiting to hear from the redistricting panel before he makes any decisions.

The group has heard a consistent set of messages.

As Western Maryland Democrats plead for a more competitive district, Democrats in Central Maryland are playing defense: They do not want to be corralled into a newly redrawn and sprawling 1st District.

Sharon Taylor of Bowie summed up the sentiment at a recent hearing in Prince George's County. She drew applause when she said African-Americans shouldn't be used as "filler" to help elect far-flung congressional representatives.

"Prince George's County cannot be the sacrificial lamb," she said.

Baltimore Sun reporter John Fritze contributed to this article.