The Supreme Court has yet to rule on partisan gerrymandering. (Jacquelyn Martin/AP)

The Supreme Court decided Monday it's OK for states to create independent redistricting commissions to draw electoral boundaries,  possibly paving the way for more state legislatures to get out of the business of drawing lines.

Monday's 5-4 decision ruled against the Republican-controlled Arizona state legislature, which sued to get its line-drawing power back from an independent commission that voters set up in 2000. (The case was literally called Arizona State Legislature vs. Arizona Independent Redistricting Commission.)

In setting up the independent commission, Arizona voters were trying to get away from partisan gerrymandering -- or the process of lawmakers carving out often-oddly shaped district boundaries to rig elections for a given politician or party. Gerrymandering has created a mess of district maps and, in the mind of some, added to polarization in Congress.

[The increasingly ugly gerrymandering of America -- in 7 maps]

Six states have some kind of redistricting commission, with another in Iowa that has considerable control over the map. But at least 11 other state legislatures use some kind of commission to help them draw lines or get over gridlock.

Courtesy: Loyola Law School

That number could increase after Monday's decision -- as states ramp up for the next round of redistricting after the 2020 Census. But drawing district lines is still a largely partisan game controlled by state legislatures, and the Supreme Court has yet to touch on that.

Here's the red/blue break down of Monday's decision:

The crux of the case

Monday decision hinged on one word in the Constitution: "legislature."

When our founding fathers said "time, places and manner of holding elections" for Congress "shall be prescribed in each state by the legislature thereof," did they mean the actual body of lawmakers in the legislature? Or was it a loose term to refer to all the people -- from voters to lawmakers-- who make up the broader legislature?

The court went with the loose interpretation. Justice Ruth Bader Ginsburg, who wrote the majority opinion, said: "The people of Arizona turned to the initiative to curb the practice of gerrymandering” and to ensure that voters chose their representatives, not the other way around. “The Election Clause does not hinder that endeavor.”

Republicans are not happy

Independent commissions like Arizona's (made up of two Democrats, two Republicans and one independent) would on the surface seem like a fairer way to draw electoral districts than giving the power to partisan lawmakers whose jobs depend on those same district lines.

But Republicans say that's a fallacy. Independent commissions should be renamed Unaccountable Commissions of Unelected People, said Matt Walter, the president of the Republican State Leadership Committee, which works to keep Republicans in control of state legislatures.

Drawing district lines is an inherently political process that for which the Constitution has set up appropriate checks and balances, he said.

Those checks? Elections. If voters don't like the way districts are drawn, they can vote their lawmakers out of office in the next election. You can't do that with an independent commission.

"We don't believe in benevolent despots," he said.

Democrats are pleasantly surprised

During oral arguments for this case in March, it didn't sound like the Supreme Court was going to go their way.

But Democrats are cheering Monday, because in upholding independent commissions' ability to draw electoral boundaries, the court is taking the line-drawing power away from many Republican legislatures like those in Arizona.

Democrats controlled the redistricting process in very few states last time around. And to this day, Republicans control a huge majority of partisan state legislative chambers -- 68 of the 98 chambers. And they're increasingly drawing lines to keep themselves in power, said former congressman Mark Schauer (D-Mich.), the director of a Democratic super PAC, Advantage 2020, which is trying to get Democrats a fighting chance in the next redistricting battle.

"Those Republican-controlled legislatures, as a result of Republican-controlled gerrymandered districts, and aren't about to create an independent nonpartisan process," he said.

Schauer thinks more states could create a commission  -- even though he points out only about half of states allow voters to set up ballot initiatives like the one in Arizona. The other half are probably stuck, because state legislators aren't going to budge and let commissions draw their districts for them.

"It's an unusual case where legislatures are going to do it by themselves and take away their power," said Joseph Sandler, an elections law expert and Washington, D.C., lawyer.

All the states but Montana (which has one congressional district because of its population) created their independent redistricting panels by ballot initiative.

Everyone's focused on 2020

For all this talk of independent commissions, the vast majority of electoral line-drawing in America is still done by state legislatures. So each side is still heavily focused on winning state elections.

For now, Schauer's goal for the 2020 election -- before the next maps are drawn off new Census data -- is to try and win at least a seat at the table in legislatures in key battleground states such as Michigan, Ohio, Pennsylvania, Wisconsin, North Carolina, Florida and Virginia -- all Republican-controlled state legislatures right now. That's the power to redraw 107 congressional seats, or about one-fourth of Congress.

It also doesn't appear the Supreme Court is going to do anything about gerrymandering anytime soon. The justices have traditionally ducked the issue because they've found it hard to create a test to measure its constitutionality, said the Washington Post's Robert Barnes.

Next term, the court will rule on how to count people within a congressional district. But it appears they'll avoid ruling on the way most districts get drawn.

One more thing

Independent commissions weren't the only thing saved by Monday's ruling. The court also essentially upheld ballot initiatives as a way to create election law, which is exactly what Arizona voters did in 2000 when they set up their independent commission.

Ruling unconstitutional the Arizona independent commission created by ballot initiative would have put in jeopardy many election laws such as Voter ID rules and changes to state constitutions that were created by ballot initiatives, a form of democracy especially popular out west, Sandler noted.

That would have been the real upheaval decision. The impact of today's decision will be revealed after the 2020 Census.