Correction: Earlier versions of this story transposed the number of congressional seats controlled by Democrats after the 2012 election. Democrats controlled six of the state’s eight seats before the election, and seven of the eight after the election.

(Jonathan Newton/The Washington Post)

Seven individuals challenging Maryland’s 6th Congressional District as unconstitutional are asking a federal court to overturn the state’s voting map or block officials from using it in the 2018 election.

John Benisek, a resident of Williamsport, and other residents allege that gerrymandering by Maryland Democrats during the 2010-2011 redistricting process violated their First Amendment rights, diminishing the ability of Republicans to elect candidates of their choice for the congressional seat now held by Rep. John Delaney (D).

Plaintiffs’ attorneys deposed some of the state’s leading Democrats, including former governor Martin O’Malley, who said he felt a responsibility to make the seat more winnable for Democrats. The seat was held at the time by Roscoe Bartlett (R), and O’Malley led the redistricting effort.

On Wednesday, the attorneys filed a motion asking a three-judge panel with the U.S. District Court in Maryland to declare the map unconstitutional or issue a preliminary injunction blocking the state from enforcing it, arguing that “any further delay risks irreparable injury with respect to the forthcoming 2018 election.”

The plaintiffs are arguing that Democratic state officials who designed the district relied heavily on advanced mapping software, voter-registration data and voting history to give an advantage to their party.

When asked whether he thought the revised district would help Democrats, O’Malley said in his deposition that it “was certainly my hope, and it was part of my intent.”

O’Malley said state legislative leaders who took part in the redistricting process, including House Speaker Michael E. Busch (D-Anne Arundel) and Senate President Thomas V. Mike Miller Jr. (D-Calvert), had the same intentions.

But Miller and Busch, in their depositions, said they did not seek to flip the district to the Democratic column. “I voted for and supported what I would believe was in the best interest of the citizens of the state,” Busch said.

Miller and Busch said they were largely unfamiliar with the data given to their staffs during the redistricting process, including metrics showing the chances of Democrats winning districts under various configurations.

“I didn’t even review it,” Miller said. “It wasn’t important to me.”

In redrawing the 6th Congressional District, state officials moved more than 360,000 residents out of the district and a roughly equal number of people into it.

Before the change, Republicans made up nearly 47 percent of registered eligible voters within the boundaries, compared with about 36 percent for Democrats. After the new lines were enacted, Republicans made up 33 percent of registered eligible voters in the district, compared with 44 percent for Democrats.

The Cook Political Report’s partisan voter index, which estimates the propensity for districts to vote Democratic or Republican, showed that the 6th Congressional District flipped from an R+13 in 2010 to a D+2 in 2011, the largest swing in the nation that year.

“There is no plausible explanation for the wholesale geographic, demographic, and political reshuffling of the Sixth District other than the attempt to dilute Republican votes to make it impossible for them to reelect Roscoe Bartlett,” the plaintiffs’ attorneys said.

Bartlett, who had consistently won reelection in the district by double-digit margins over two decades, lost the 2012 election to Delaney.

The result gave Democrats seven of Maryland’s eight congressional seats. They previously controlled six.

The plaintiffs’ attorneys claim that many constituents in and around the 6th District have been “chilled from participating in the political process, not only because they feel that voting is a lost cause in light of gerrymandering, but also because they feel disconnected from their congressional district.”

During the depositions, Miller was asked about talking points his staff had provided for various speaking engagements at Democratic events. One of the items said the revised 6th District “gives Democrats a real opportunity to pick up a seventh seat in the delegation by targeting Roscoe Bartlett.”

Another memo said: “If asked about redistricting, keep it simple. We’re going to do our best to help Democrats, while following all of the applicable federal and state constitutional and statutory requirements.”

Miller played down the talking points, saying he generally speaks off the cuff during speeches. He described the notes as “political rhetoric” designed to inspire Democrats and not necessarily guiding principles for the redistricting process.

The case is Benisek v. Lamone.