O'Malley spoke after back-to-back meetings in the State House with Rep. Christopher Van Hollen, a Montgomery County Democrat, and Rep. Roscoe G. Bartlett, a Western Maryland Republican.
O'Malley said he would consider their suggestions before submitting a final proposal to the General Assembly this month.
A panel appointed by O'Malley released a proposed map Monday for Maryland's eight congressional districts, a process required once a decade to reflect population data collected in the census.
Under the proposal, Bartlett's generally conservative district would take on a huge swath of the Washington suburbs and shift from a safe Republican seat to a toss-up. But Van Hollen, a rising Democratic star, also would see a reduction in Democratic voters in his suburban Washington district.
Van Hollen had little to say to reporters as he left the meeting. "We discussed some issues," he said. "I like my current district. I'm looking forward to meeting new people."
Bartlett said his meeting had been cordial. But he said he told O'Malley that the state could face a lawsuit over minority representation unless changes were made to the map. "They want three minority districts. Hispanics don't want their votes split. That is the problem," Bartlett said, declining to specify whom he had spoken with.
He would not say whether he would join such a suit, but did say he still plans to run for re-election.
In a written statement released by his office moments after he left the meeting, Bartlett appeared to question whether the proposed districts adequately represent minorities. Insufficient minority representation is an argument frequently cited in redistricting lawsuits nationally.
An analysis released by the Maryland Democratic Party shows that in making Bartlett's district more Democratic, the map makes Van Hollen's district significantly less so. Almost 74 percent of 8th District voters cast a ballot for the Democrat in the 2010 congressional election; the percentage drops to 60 percent for voters living with the proposed new boundaries.
Van Hollen has since 2003 been representing a district that — until the last redistricting process — had long been represented by Montgomery County Republican Constance A. Morella. Democrats in Annapolis made clear 10 years ago that they redrew the district to pack it with Democratic voters in a successful attempt to oust Morella.
This time, the map drawers felt some Republicans could be added to the district in a "rebalancing" effort, according to a Democratic source familiar with the map-drawing. Van Hollen, who has a national profile, would have an easier time introducing himself to new voters than a less prominent member of the delegation would, the source said.
The proposed changes in the 8th District were enough to cause one Republican state lawmaker to take a look: State Sen. David Brinkley said he's "considering" mounting a challenge to Van Hollen but "needs lots of information" before he decides. The three-term Frederick County senator lives on a farm near Mount Airy, in what would be the new 8th District.
Several independent political observers said they doubted the new district would present a major challenge for Van Hollen.
"I don't think he's in any jeopardy," said Donald Norris, chairman of the public policy department at the University of Maryland, Baltimore County. "If it is around 60 percent, that is a slam-dunk, isn't it?"
Nathan L. Gonzales, deputy editor of the nonpartisan Rothenberg Political Report, noted Van Hollen's recent two-term stint as chairman of the Democratic Congressional Campaign Committee, a position that won him potential allies across the country.
"This is a classic challenge with redistricting: Even though Democrats control the process, there are still tough decisions to be made," Gonzales said. "If Democrats want to maximize their numbers in the delegation, then the Democratic members have to be willing to represent fewer Democratic voters."
Gonzales said he doubts the new district would slow Van Hollen's rapid rise in Democratic leadership circles.
In fact, the changes could benefit Van Hollen should he decide in the future to run for the U.S. Senate, said David Wasserman of The Cook Political Report. It could be "helpful" for Van Hollen to show he can appeal to rural voters, he said.
The publication now rates Bartlett's district to a toss-up. But, Wasserman said, the authors plan to leave Van Hollen's as "solid Democrat."