The U.S. Supreme Court’s recent decisions on ObamaCare and same-sex marriage got nearly all the media and public attention. But the court decided other issues, supporting the use of lethal injection when states impose the death penalty and curbing the Environmental Protection Agency’s power to limit emissions from power plants.

But another big issue, one that could help improve the effectiveness of Congress, involved the high court’s ruling on redistricting — the redrawing of electoral districts to reflect population changes in national census figures updated every 10 years.

In a 5-4 decision, the court ruled independent redistricting commissions do not violate the Constitution, which was the argument made by Arizona’s Republican-controlled Legislature when a statewide voter referendum approved moving redistricting powers to an independent commission comprised of two Republicans, two Democrats and one independent.

Redistricting is a neutral-sounding word describing the drawing of new political boundaries. But in reality, redistricting is better described by the more colorful and descriptive term, gerrymandering.

That historical name was created to describe a tortured redrawing of a Massachusetts district that looked like a salamander, with a head, long tail, legs and claws. The redrawing was done by Gov. Eldridge Gerry of Massachusetts in 1812 and was designed to benefit Gerry’s then Democratic-Republican party. With that politically motivated redistricting, the term gerrymander was born.

Since then, lawmakers have been gerrymandering for more than a two centuries. But a long history is no reason for the practice to continue. Many political analysts argue gerrymandering is a root cause behind today’s highly partisan politics.

As practiced by most lawmakers in most states, redistricting reverses the old civics class lesson that says in a democracy the voters choose the politicians. With gerrymandering, the politicians choose their voters by carving districts into distorted shapes to include or exclude voters of one party or the other. these oddly shaped voting districts create a so-called safe seats for either Republicans or Democrats.

Today, it’s about creating more safe seats because for the past few decades, few congressional districts see competitive elections. Incumbents typically win with ease, getting re-elected at a rate of 90 percent or more. They have money-raising advantages and the gerrymandering makes it even tougher for a true challenger to beat the incumbent in November. Most experts agree that there are only 40 to 60 competitive congressional elections in the 435 districts across the country.

Gerrymandering is done by both political parties, so it’s not a Democrat or Republican abuse, though with more state legislatures controlled by the GOP in recent years, Republicans have been behind most recent gerrymandering efforts.

Gerrymandering is an incumbent-protection process. It’s also undemocratic. That’s the motivation behind states taking the redistricting process away from politicians and moving it to nonpartisan commissions.

About a dozen states have some form of the commission-based redistricting process. In some, the commission draws the new district lines. In others, the commission draws the lines, but the legislature must approve.

California voters approved the shift in 2008, and most observers believe more competitive elections are the result.

State lawmakers have repeatedly shown they will abuse the line-drawing powers of redistricting for political gain. Noncompetitive races are the result. And noncompetitive races are good for incumbents, but not good for voters.

The Supreme Court made the right decision in backing commission-based redistricting. Democracy will work better if more states take the power to draw political boundary lines away from politicians.