The changes would further diminish the city's power in the General Assembly and reflect a population drain in Baltimore over the past decade — when the rest of the state has grown. The city's voting strength in the legislature would be less than half of what it was in the 1970s under the new plan.
Annapolis — because Baltimore County gains two delegates — and would continue to have seven majority African-American districts. "The region was preserved even as the city lost population," said Joseph C. Bryce, the top legislative aide to O'Malley, a Democrat.
House Speaker Michael E. Busch said that "on balance everybody should be really happy, Democrats and Republicans." The Anne Arundel County Democrat said that the process has been stressful but that the final product is "a pretty fair map."
The new map, which will be considered by the General Assembly in the legislative session that begins in January, would also reconfigure political lines in Baltimore County, turning one Senate seat currently held by a Democrat into potential pickup for the GOP.
And lines would be redrawn in an attempt to bolster minority representation.
The map would add two more Senate districts with a majority of African-American voters in Prince George's County, and for the first time create a House of Delegates district in Prince George's County that is majority Hispanic. The panel left open the possibility for a second majority-Hispanic seat in Montgomery County and plans to ask for public comment on the idea.
The unveiling of the map Friday followed weeks of frantic negotiations, during which details of the map leaked, causing confusion and angst. House Judiciary Chairman Joseph Vallario said he jokingly considered attending a media briefing on the plan to get a firm rundown of the details.
O'Malley can still make changes to the proposed map and plans to hold a public hearing Thursday. The final version would be in effect for the 2014, 2018 and 2022 elections.
The state's constitution requires that O'Malley introduce his version of the map as a joint resolution on the first day of the legislative session, but it won't necessarily come to the General Assembly for a vote. The House and Senate will have 45 days to fiddle with it. If they fail to agree on changes by then, the governor's map becomes law.
Though the proposed map alters the borders of the state's 47 Senate districts, those who drew it said they tried to contain most districts to a single county. Ten years ago, the map drawn by Gov. Parris N. Glendening, a Democrat, was tossed out by a state judge and redrawn by the courts because it included "an excessive number of political subdivision crossings."
The new map is the result of six months of work by O'Malley's five-member panel, which included Busch and Senate President Thomas V. Mike Miller, also a Democrat.
Over the summer, the group crisscrossed the state, holding a dozen hearings. The same group drew a new congressional map in October that stoked partisan rancor because it remade a reliably GOP Western Maryland U.S. House district into a tossup. A federal court challenge to that map funded by a national conservative group is set for a hearing Tuesday.
The state map, however, did not provide any obvious partisan advantage, and the sole GOP member of the redistricting committee, former Del. James King, voted for it. "It was done with a lot of thought," King said. "All in all, the map is not a net gain for the Democrats."
Fewer than one-third of the members of Maryland's state legislature are now Republican, a proportion slightly higher than the number of Republicans in the state, who make up a quarter of the electorate.
The plan also creates two more majority-minority districts in areas where a combination of Hispanics, Asians and blacks outnumbers the white population. In 2002, the last time the map was redrawn, there were two such districts.
The state's Legislative Black Caucus had lobbied for more majority black districts. "There needed to be an increase because of the growth in the African-American communities," said state Sen. Catherine E. Pugh, a Baltimore Democrat who chairs the caucus. She withheld judgment on the new plan until she could study the lines.
The plan radically redraws Baltimore's 44th Senate District, which lost 25,144 people in the last 10 years — shrinking more than any other in the state. Under the proposed map, the 44th stretches into western Baltimore County in a hybrid city-county Senate seat.
Sen. Verna Jones-Rodwell, who now holds that seat, said earlier this week that the proposal would meet her goal of ensuring that the city has six senators. "It is really important to have the representation in the Baltimore metro area," she said.
The smaller city portion of her district includes the Bolton Hill home of freshman Del. Keiffer Mitchell, a Democrat who may launch a run for a seat in the other chamber. In addition, the homes of the other two delegates currently representing the district, Keith Haynes and Melvin Stukes, would be moved to the 40th and 41st, respectively. That sets up two House races in 2014 where incumbents would be forced to run against each other.
Pushing part of Jones-Rodwell's district into the county sets off a wave of changes. Sen. Delores G. Kelley, the county's only African-American senator, would have a district that's still majority black, but less so.
Sen. Robert Zirkin picks up Democrats from Pikesville, a municipality that is reunited under him under the plan.
Most dramatic is the change to the district represented by Democratic Sen. James Brochin, who has opposed O'Malley on several issues, including his 2007 tax package. Brochin's seat would have a majority of Republican voters under the new map. Four delegates — three of them Republican — live in that new district.
Brochin's new geographic area starts in Towson and runs north, nearly hitting the Pennsylvania border. "They certainly did everything they could do to make my political life difficult," he said.
Other significant shifts come around the Washington suburbs, particularly in Prince George's County, which did not grow as fast as the rest of the state.
The district represented by Miller shifts more into Calvert County, where Miller lives. Also, the new version of his district pulls in a small portion of Charles County, giving the powerful Senate president a vote in three county delegations.
In 2002, a proposed map was drawn to give Miller a district that included four counties: Charles, Calvert, Prince George's and Anne Arundel. But the map was redone by a judge who left him with only part of Prince George's and Calvert.
In a surprising move, the district held by Vallario, a Democrat who now represents Calvert and Prince George's counties, is moved north into a new area. "I'm very much going to miss my old district," Vallario said. "I'm not happy about that at all."
The district held by Busch also would change. He would lose some Republicans from the Broadneck peninsula.
Baltimore Sun reporter Michael Dresser contributed to this article.