WASHINGTON (AP) -- Groups trying to curb the partisan sculpting of House districts are hoping their Supreme Court victory will prompt more states to create independent commissions to redraw congressional lines.
But Republicans scoffed that Monday's 5-4 decision upholding Arizona's independent redistricting commission would have little impact. With the GOP's current House majority aided by their domination of congressional line drawing in many states, some Republicans conceded that reducing that power could hurt them but would be hard for opponents to achieve.
"It's a sweeping decision that lays the groundwork, but the work still has to be done" by advocates of independent commissions, said GOP strategist Sean Noble. "And whether they have the time, money or will has yet to be determined."
Proponents of siphoning partisanship from the process said they're already trying.
They will rely partly on the same method Arizona used to create its independent commission: Initiatives, when voters directly place questions on the ballot without the state legislature's involvement, usually by acquiring signatures on a petition. Monday's court ruling kept that option open.
Twenty-four states allow initiatives and had votes on 2,421 statewide questions from 1900 to 2012, according to the Initiative and Referendum Institute at the University of Southern California law school. About 4 in 10 were approved.
Kathay Feng, national redistricting director for the liberal Common Cause, said efforts to use initiatives to alter how district boundaries are drawn are under way in Illinois, Michigan and Ohio. In three other states, supporters are working through the legislature: Indiana, Maryland and North Carolina, she said.
The court's ruling "preserves one of our best tools to stop partisan gerrymandering," the drawing of district lines to benefit a political party, said Lloyd Leonard, advocacy director for the League of Women voters, which filed a brief backing the commission.
House Speaker John Boehner, R-Ohio, "believes redistricting decisions are best made by the people's representatives in state legislatures - not by some unelected, unaccountable board of bureaucrats," said Boehner press secretary Olivia Hnat.
House Minority Leader Nancy Pelosi, D-Calif., backed the court decision and said Congress should set standards so state redistricting commissions "reflect the diversity of their states and communities, and it must be founded on a full and fair count of the Census."
Congressional districts are redrawn every decade to reflect the latest Census.
In Monday's ruling, the justices rejected a challenge by Arizona's Republican-led legislature to the state's independent commission, which voters established by ballot initiative in 2000. Arizona's congressional delegation currently tilts 5-4 to the GOP, which has complained that the commission-drawn lines have disproportionately helped Democrats.
The legislators argued that the Constitution reserves the power to draw district lines to state legislatures, not a commission created by initiative. That argument was rejected by the court's four liberal justices plus Anthony Kennedy, a frequent swing voter.
"The invention of the initiative was in full harmony with the Constitution's conception of the people as the font of governmental power," Justice Ruth Bader Ginsburg wrote.
The dissenters were led by Chief Justice John Roberts, who said the majority relied on "disconnected observations about direct democracy, a contorted interpretation of an irrelevant statute, and naked appeals to public policy."
The decision left the status quo intact for Arizona and 12 other states that have commissions with varying roles in drawing congressional lines.
A victory for Arizona's legislature probably would have led to new House district lines with 1 or 2 additional GOP seats in Arizona, which also has a GOP governor.
But Democratic-run California, the biggest state, has a similar redistricting commission and was viewed as likeliest to also have to redraw lines for its 53 districts.
That could have produced "a blood-letting" for California Republicans, said former GOP Rep. Thomas Reynolds of New York, who headed his party's House campaign efforts in the early 2000's. California's House delegation is already dominated by Democrats 39-14.
Overall, Republicans have a 246-188 House majority, plus a vacancy in one GOP-leaning district.
Analysts attribute part of that advantage to Democrats' concentration in dense urban areas, but it also reflects district lines Republicans drew after making major gains in 2010 state elections. In 2012, GOP House candidates got 1.4 million fewer votes than Democrats but won a 33-seat majority.
The GOP controls the governorship and legislature of 24 states, including Nebraska's officially nonpartisan legislature. Seven states are run by Democrats and 19 are split, according to the National Conference of State Legislatures.
"Democrats have benefited every bit as much from gerrymandering as Republicans in states they control," said GOP political consultant Whit Ayres.
But those looking to limit partisan-driven districts say Monday's ruling was a big win.
"It preserves the option of reform" in states with initiatives, "even if the legislature and governing class are recalcitrant," said Michael Li, counsel at the New York University Law School's Brennan Center for Justice, which filed a brief supporting Arizona's commission.
Copyright 2015 The Associated Press modified.