The Supreme Court said Monday it will decide whether Republican lawmakers in Wisconsin drew electoral districts so out of whack with the state's political breakdown that they violated the constitutional rights of Democratic voters.

  • Supreme Court will hear Wisconsin gerrymandering case
  • Republicans accused of violating Democratic voters' constitutional rights
  • Ruling could have far-reaching implications for other states

What the Republicans did is called gerrymandering, a centuries-old practice of creating legislative districts that favor one party over another. Both political parties do it when they can.

SO EXACTLY WHAT IS GERRYMANDERING?

Gerrymandering is the practice of one party packing as many voters of the other party into the fewest districts possible.

The term comes from a Massachusetts state Senate district that resembled a salamander and was approved in 1812 by Massachusetts Gov. Elbridge Gerry.

Every 10 years following the census, states redraw the boundaries of legislative districts to account for population changes, so that the number of people living in each district is about the same. The generic term for the process is called redistricting.

States redraw districts for House seats in Congress and for legislative districts in state legislatures. Cities do it for city council districts.

But there are efforts to stop gerrymandering across the country and replace it with bipartisan map makers and other systems.

In Florida, voters approved the Fair Districts amendments in 2010 with 63 percent of the vote. The amendments required legislative and congressional districts be drawn as equal in population as feasible, can't benefit an incumbent or political party.

The Fair Districts group took the Republican Florida Legislature to court after they found the districts drawn in the wake Fair Districts vote did not conform to the spirit of the amendments.

The state was eventually forced to use court-ordered congressional maps for its new districts, which led to changes for several lawmakers on both sides of the aisle.

ON TO WISCONSIN

The Wisconsin case involves the state legislature. In Wisconsin, the Republicans were in charge so they tried to pack as many Democrats as they could into the fewest number of districts.

This left fertile ground in the rest of the state for Republicans to win more legislative seats.

WHO DRAWS THE LINES?

In most states, the redistricting process is controlled by the state legislature and the governor, which is why state elections at the beginning of each decade are so important. In other states, bipartisan commissions draw districts in an effort to reduce gerrymandering.

Gerrymandering has become more precise as computer software has become more sophisticated, enabling map-makers to divide counties, cities and even neighborhoods to maximize their political advantage. The result has been sprawling, odd-shaped districts that might include communities with little in common other than the residents' political affiliation.

The Supreme Court has repeatedly ruled that states cannot gerrymander districts in an effort to reduce the influence of minority voters. But the court has never struck down a legislative map for strictly political reasons.

___