Once a decade, during every year that ends in zero, there's a national census, followed by a constitutionally mandated round of reapportionment to determine how many representatives each state will send to Congress. Congressional districts and state legislative districts must then be redrawn to reflect changes in population. In 34 states, the new congressional maps are generated by the state legislature or by commissions under legislative control. Not surprisingly, legislators often make politically motivated district maps, or gerrymanders. Sometimes incumbents from both parties cooperate to protect their seats. Other times the party in power draws maps to lock down majorities and to disadvantage the opposition.
The Republican State Leadership Committee has a specific task force that works to ensure districts are redrawn to favor their candidates, known as REDMAP. The project was especially effective in Michigan, where the committee spent $1 million in 2010 to guarantee a map drawn in their favor.
The Republicans in charge of drawing the maps shifted the borders of districts to put just enough Republican voters into a large number of districts in order to win them safely, and put many more Democrats into districts that were already overwhelmingly Democratic in order to limit the influence of their votes. Experts call these tactics "cracking" (spread out voters to give yourself a small but safe advantage in many districts) and "packing" (pack your opponents into as few districts as possible). In 2016, Michigan Republican House members won their districts by a 21.6 percent margin of victory on average. Michigan's winning Democrats averaged margins of 40.6 percent. Winning districts by large margins is inefficient—just as losing by small margins is inefficient. It "wastes" a lot of votes by not translating them into seats. Social scientists call the difference in the percentage of votes each side wastes an "efficiency gap"—a metric that can be used to quantify partisan gerrymandering.
Opponents of gerrymandering argue these maps don't just invalidate voting blocks, they cause widespread misrepresentation. In a New York Times op-ed that ran shortly before the 2018 midterm elections, Chad McEvoy, a Democratic candidate for the 101st New York Assembly District, said that if he won the district, he would work to fundamentally restructure it. The 101st most closely resembles a snake currently, covering an insanely long swath of New York state.
The district comprises 25 mostly rural townships carved out of seven counties in a narrow north-south line rarely more than a single town wide. It runs about 200 miles, from the Mohawk Valley through the Southern Tier and into the Hudson Valley. It spans three congressional districts, four State Senate districts and 36 school districts.
The northern tip includes the suburbs of Utica, while the southern end dips into Orange County to encompass a couple of New York City commuter towns. This last fact never fails to blow the minds of my neighbors in the 850-person dairy farming town of Westford, for whom New York City might as well be on another planet.
...Take just one concern: water. The suburban areas of New Hartford, near Utica, have complex issues regarding storm water drainage and flooding, while decades of underinvestment in infrastructure has left the residents of the village of Ilion, in nearby Herkimer County, with brown municipal water flowing from their faucets. The town of Delhi and the surrounding areas in Delaware County, in the middle of the district, fret about the stifling economic effects of being ringed by New York City-owned watershed land, while in my town, one hour north, every household has its own well water and septic tank, and no municipal water services are available at all.
In June 2019, the Supreme Court ruled federal judges had no authority over partisan gerrymandering. While the courts can effect change on gerrymandering ruled racially biased, the Justices did not believe politically motivated gerrymandering was in their purview. Democratic candidates for president came out en masse to decry the ruling. Per the Washington Post:
Democratic presidential candidates, ahead of the second round of the first Democratic debate, pledged to fight to overturn the ruling if they win the White House next year.
Warren said she would seek to require states to use independent redistricting commissions to draw political districts rather than leave that task to governors and state legislatures. Warren added that if Senate Republicans tried to block her legislation, she would seek to end the use of the filibuster in the chamber.
Doing so would allow legislation to pass with a simple majority rather than with the 60 senators currently required to cut off debate on most bills.
Sen. Kamala D. Harris (D-Calif.), another 2020 hopeful, said a ban on partisan gerrymandering would be a priority for her if elected.
“Politicians shouldn’t be able to pick their voters, voters should choose their representatives,” Harris said. “The Supreme Court’s gerrymandering decision will have drastic consequences for the future of our nation.”
Not everyone agrees that gerrymandered districts disenfranchise minority voters. In a study for Vox, researchers found that these districts can actually enhance and protect minority votes. Some Democratic lawmakers agree:
When Pennsylvania Democrats went to the Supreme Court in 2004 to ask that Pennsylvania’s GOP-drawn congressional map be struck down as an unfair partisan gerrymander, they drew opposition from an unexpected source: fellow Democrats.
Alabama Democrats told the court in a brief they were concerned that ending partisan gerrymandering would “undermine … the ability of African Americans in Alabama to continue the effective exercise of their newly won ability to participate in the political process.”
In 2001, they pointed out, “African-American representatives pulled, hauled, and traded with their white colleagues” to achieve greater representation.
In short, political gerrymandering — in which it was taken for granted that Democrats sought an advantage — helped maximize the voice of African Americans.
Conservatives are quick to point out that politicians typically only have issues with gerrymandered districts when they are not in their own favor. Democrats are more than happy to redraw districts to fence in specific minorities and types of voters when those voters are going to elect them. A New Yorker article from 2008 describes Barack Obama working with Democratic strategists to do just that when he was running for an Illinois seat.
On the screens that spring day were detailed maps of Chicago, and Obama and a Democratic consultant named John Corrigan sat in front of a terminal to draw Obama a new district. Corrigan was the Democrat in charge of drawing all Chicago districts, and he also happened to have volunteered for Obama in the campaign against Rush.
Obama’s former district had been drawn by Republicans after the 1990 census. But, after 2000, Illinois Democrats won the right to redistrict the state. Partisan redistricting remains common in American politics, and, while it outrages a losing party, it has so far survived every legal challenge. In the new century, mapping technology has become so precise and the available demographic data so rich that politicians are able to choose the kinds of voter they want to represent, right down to individual homes. A close look at the post-2000 congressional map of Bobby Rush’s district reveals that it tears through Hyde Park in a curious series of irregular turns. One of those lines bypasses Obama’s address by two blocks. Rush, or someone looking out for his interests, had carved the upstart Obama out of Rush’s congressional district.
Some Democratic legislators said that while they did not agree with the Supreme Court's ruling, and would continue to work against the practice of partisan gerrymandering, they would use the tools at their disposal to win back these seats. Per the Daily Beast:
As they digested the decision, however, a rift emerged among them over whether or not the high court’s decision amounted to a free pass for Democratic-run states to go nuts on drawing the most advantageous lines possible for the party in power.
Some leaned into the realpolitik.
“I don’t see how there’s any other options,” argued Rep. John Yarmuth (D-KY), “because Republicans will do it in the states they have the ability to do it.”
The lone Democrat in Kentucky’s congressional delegation, he predicted the GOP in the Bluegrass State would try to “break his district.”
“I wouldn’t blame any state Democratic legislature for taking full advantage of it,” Yarmuth continued. “Clearly it’s a license at the federal level to do whatever you want, to be as partisan as you want to be.”