PHOENIX (AP) — Republican leaders in the Arizona Legislature are pushing a proposal to dramatically overhaul the independent commission that draws congressional and legislative maps every decade.

Redistricting is important because it can decide which party gets the majority of congressional and state legislative seats. It is a contentious issue nationwide.

Senate President Steve Yarbrough's proposal would expand the Arizona Independent Redistricting Commission from five to eight members, all appointed by the Legislature. Three would be Democrats, three Republicans and two independents.

"My great hope is that this is going to result in a necessity that we get bipartisan maps," Yarbrough said. "Because those two independents are highly likely to be partisan independents, if there is such a thing. You effectively have two groups of four — they're going to have to come together and compromise to get to five."

He pointed to commissions in 2001 and 2011 that he said were essentially controlled by the one independent, who could side with either Democrats or Republicans to sway the process.

"In 2001 the Republicans more or less controlled the redistricting process, in 2011 the Democrats absolutely seized control of the process," Yarbrough said. "This would make it much harder for that to be pulled off by either party."

Under Yarbrough's proposal, if the GOP-controlled Legislature didn't like the maps they created, they could draw their own and ask for voter approval.

Joel Edman of the Arizona Advocacy Network called Yarbrough's plan "a recipe for partisan gridlock," He said allowing the Legislature to draw up its own map gives Republicans on the panel no incentive for compromise.

Edman also said voters who will have the final say will likely see the proposal as he does — an effort by the Republicans who control the Legislature to make the current commission structure less independent and give politicians greater ability to draw their own districts.

"The voters know a power grab when they see one and I think that's what they're going to see if this comes up on the ballot," Edman said.

Voters approved the Arizona Independent Redistricting Commission in 2000 in an effort to cut state lawmakers they saw as drawing districts that favored themselves out of the process. Potential members of the five-member panel are screened by a state commission that recommends judges for the appeals courts, with Democratic and Republican legislative leaders then choosing two members each from their party to serve. Those four then pick an independent as the chair.

The panel is required to draw equal-population districts and take into account goals that include communities of interest, compactness and competitiveness - whether individual districts could realistically be won by both major parties' candidates.

After the 2001 and 2011 maps were adopted, they were challenged in court. Democrats sued over the 2001 maps and Republicans over those drawn in 2011. They were upheld in each case.

Yarbrough's proposal passed the Senate committee Wednesday on a 4-2 party-line vote and now goes to the full Senate. If approved by the Senate and House, voters would weigh in on the changes in November.

— The legislation is SCR1034