New map, new politics in Western Md.

With a bit of math and a few clicks of a mouse, state Democrats transformed a once-sleepy congressional district in Western Maryland last week into one of the most closely watched political battlegrounds in the nation.

Hours after Gov. Martin O'Malley signed his controversial redistricting plan into law, potential candidates and powerful third-party groups began jockeying for position in the redrawn 6th District, which now stretches from the state's western border to the suburbs of Washington.

Not only will the race put Maryland in the national spotlight for the 2012 election, it will give state voters a hand in deciding the balance of power in Congress at a critical time for the U.S. economy. The district now held by 10-term Republican Rep. Roscoe G. Bartlett offers Democrats one of perhaps a dozen opportunities across the nation to increase their numbers.

The 6th District race has drawn the attention of many of the outside political groups that pumped cash into tight contests in the 2010 election, an indication that it could take millions of dollars to win.

That could pose a problem for Bartlett, who spent $367,000 over a two-year period to win re-election in 2010. In the past three months, his campaign took in a mere $1,000.

One Democratic consultant estimated that the 2012 race would cost $500,000 a week for television advertising alone.

"It is going to be like the Civil War," said Maryland Senate President Thomas V. Mike Miller, noting that one of America's most famous battlefields is located in the district. "It is going to be the North and South coming together right there in Antietam, battling all over again."

O'Malley, a Democrat, signed the map into law Thursday after a four-day special session of the General Assembly.

The 6th District previously spanned mostly rural, conservative enclaves from Garrett to Harford County. The district's new boundaries extend south into more suburban and Democratic-rich sections of Montgomery County.

Forty percent of the voters in the former 6th District cast ballots for Barack Obama for president in 2008, compared with 56 percent in the redrawn district.

The state's ruling Democrats drew the new congressional districts, a process required every decade to reflect population changes. Unless altered in court, the new map will govern Maryland elections to the House of Representatives for the next 10 years, starting with the April 3 primary.

The new 6th District is not necessary a slam dunk for Democrats — particularly given concerns over the economy and nose-diving poll numbers for Obama — but it nevertheless is a big opportunity.

"It's a prize," said Larry Sabato, director of the University of Virginia Center for Politics. "When you've got a seat like that that is switchable, you're going to have millions" spent on advertising.

After historic wins in the 2010 midterm elections, Republicans enjoy a 50-seat advantage in the House.

Several voters in the district said they welcome the looming political contest but question the methods state leaders used to achieve it.

"It's fine to have a competitive race," said Alan McVay, a 58-year-old independent voter from Gaithersburg. "But I think the districts ought to correspond more to counties and municipalities and not to some arbitrary line."

A bevy of potential candidates from both parties is circling the district, including Democrat Doug Duncan, a former Montgomery County executive, and Duchy Trachtenberg, a former member of the Montgomery County Council. Trachtenberg is the only high-profile Democrat who has officially announced a run for the congressional seat.

Duncan did not return several phone calls seeking comment.

State Sen. Robert J. Garagiola, 39, is another potential candidate who could draw considerable support.

The Montgomery County Democrat released a statement that he is "seriously considering" a run. Earlier in the month, he filed paperwork with the Federal Election Commission required for candidates who intend to raise money for a federal race.

Known as an energetic campaigner and prodigious fundraiser, Garagiola has also quickly developed a statewide network of support that could propel his candidacy.

Moments after the state Senate gave final approval to the map, colleagues began wishing Garagiola well in the race. Sen. Katherine A. Klausmeier, a Baltimore County Democrat, pretended to wipe away tears and sang a goodbye song as she walked by him in the State House.

But Garagiola also has a record in Annapolis that will be heavily scrutinized in the new, centrist district.

He was the lead sponsor of a bill that sought to legalize same-sex marriage, introduced a $471 million package of tax and fee increases that would have raised the state's gas tax by 10 cents, and voted to give some illegal immigrants tuition breaks at Maryland colleges and universities.

Both same-sex marriage and the in-state tuition measure could be on the 2012 ballot.

"If someone asks me a question out in Allegany County about same-sex marriage, I'm going to talk about it and explain my reasoning for it," Garagiola said. "Hopefully, those who are like-minded will be appreciative of it, and those who aren't will at least understand my reasoning for it."

The potential field is less clear on the Republican side, partly because many are waiting for Bartlett's next move. While he has said that he plans to seek re-election, he has not granted interviews since the redistricting process got under way and his recent lackluster fundraising has fueled speculation that he might retire.

In 2010, House races drawing similar national attention carried price tags near $10 million. Experts say it would be difficult to raise that much money in the new 6th District alone, meaning that candidates would have to find money out of state.

It is also not clear whether Bartlett, 85, would have the full support of the Republican Party. He has occasionally bucked GOP leaders in Washington — particularly on energy and climate change — and has maintained tenuous ties with some of the state's Republican leaders.

The chairman of the Maryland GOP, Alex X. Mooney, a former state senator from Frederick, is a possible candidate for Bartlett's seat. Other Republicans considered to be in the mix but who have not stated their intentions include state Sen. Christopher B. Shank of Washington County and Frederick County Sheriff Charles A. Jenkins.

Jenkins is known for his hard-line stance against illegal immigrants. His is the only local law enforcement agency in the state with a policy that requires that illegal immigrants be referred to federal authorities. By his count, the policy has led to 800 deportation proceedings.

Through a spokeswoman, Jenkins declined to be interviewed.

Third-party political groups, meanwhile, are also watching the fast-changing landscape in Western Maryland. Ryan Rudominer, a spokesman for House Majority PAC, said his group is keeping a "close eye" on what he described as a potentially "very competitive race." The Washington-based political action committee raises money to help Democrats in competitive elections.

The campaign arms of the Democratic and Republican House caucuses are also beginning to engage.

In a statement that was heavily critical of Bartlett, Democratic Congressional Campaign Committee spokesman Josh Schwerin said that the new district will give voters a chance to elect "a fresh face who will fight for middle-class jobs."

Tory Mazzola, a spokesman for the National Republican Congressional Committee, countered that Bartlett has a long record of supporting job creation.

Asked whether the group would help augment Bartlett's fundraising with its own advertising campaign, Mazzola replied: "Congressman Bartlett will have the resources that he needs."