Sens. Delores Kelley and James Brochin, both Democrats, asked the Maryland Court of Appeals to invalidate the redistricting plan, which automatically took effect this year when the legislature did not move to replace Gov. Martin O'Malley's plan with one of its own.
Assistant Attorney General Dan Friedman, counsel to the General Assembly, expressed confidence that the plan will be upheld by the state's highest court, which hears challenges to legislative redistricting.
"The plan is constitutionally and legally sufficient, and we look forward to defending it," he said. The suit was one of four filed Tuesday, the deadline for challenges to the redistricting plan.
The governor and legislature are required to redraw congressional and legislative districts every 10 years to reflect the results of the U.S. census. The legislature adopted a congressional redistricting map in a special session last year. So far it has withstood legal challenges.
In their suit, Brochin and Kelley contend that by extending the 44th District across the city-county line, the map violates a state constitutional requirement that "due regard" be given to political boundaries between subdivisions.
The incumbent senator in the 44th is Verna Jones-Rodwell, a Democrat who lives in the city. If she can hold on to the seat, Baltimore City would likely continue to be home to six resident senators. Brochin and Kelley contend in their suit that the city was entitled to only five districts, wholly contained within its borders.
Brochin said Wednesday that the map "was all about making sure the city didn't lose representation, even though it lost population, which violates the concept of 'one man, one vote.'"
The three-term senator noted that Baltimore County's population had increased. "We should have picked up a senator," he said. "As soon as I saw the map, it just reeked of partisanship."
But Jones-Rodwell rejected the implication that she could not effectively represent county residents. She said there is a strong "community of interest" between the city part of her district and the part of the county in Woodlawn and along Liberty Road. She said most of the residents of those areas of the county are former city residents.
"I have no doubt in my mind that I could represent them very well and bring resources Baltimore County has not had," said Jones-Rodwell, a member of the powerful Budget and Taxation Committee.
Other suits challenging the map were filed by three parties who are not members of the legislature.
Towson Times reporter Jon Meoli contributed to this article.