AUGUSTA, Maine — Maine’s highest-powered Republican couple — former U.S. Sen. Olympia Snowe and former Gov. John McKernan — have signed onto briefs urging the U.S. Supreme Court to limit gerrymandering when it decides a potential landmark case later this year.

The high court will hear arguments in October in the case of Gill vs. Whitford, which challenges redistricting maps drawn and signed into law in 2011 by Republicans in Wisconsin, calling it an unconstitutional example of gerrymandering, the act of manipulating political boundaries to benefit a party or class.

In 2016, a three-member panel of federal judges agreed, but the state appealed to the Supreme Court. Upholding that decision could have a large impact on districts across the nation.

Republicans’ advantages in state legislatures have given them outsized control of congressional maps and an Associated Press analysis found that they won 22 seats in the U.S. House of Representatives over what would be expected given the average national vote share.

Snowe, who served in both chambers of Congress from 1979 to 2013, and McKernan, her husband who served alongside Snowe as a congressman before winning two terms as governor from 1987 to 1995, signed onto briefs organized by the Campaign Legal Center, a national group that fights gerrymandering.

“The promise of the United States Congress is finding common ground to solve America’s greatest challenges,” Snowe said in a statement. “Unprecedented levels of partisanship and polarization have degraded that promise and extreme partisan gerrymandering deserves a share of the blame.”

Snowe was one of 36 current and former members of Congress to sign onto their own brief supporting the plaintiff alongside U.S. Rep. Chellie Pingree, a Democrat from Maine’s 1st District, while McKernan joined a group of current and former statewide elected officials led by Ohio Gov. John Kasich and former California Gov. Arnold Schwarzenegger.

The AP analysis found that redistricting had little effect in Maine, which has only two congressional districts. In 2011, Democrats complained when Republicans proposed splitting the state in population halves from north to south instead of east and west, but a deal was struck that made few changes.

Michael Shepherd

Michael Shepherd joined the Bangor Daily News in 2015 after three years as a reporter at the Kennebec Journal. A Hallowell native who now lives in Augusta, he graduated from the University of Maine in...