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Story highlights

The decennial line-drawing process has always been a somewhat political endeavor

In most states, state legislators and the governor control the process

(CNN) —  

The Supreme Court heard arguments Tuesday on a case with massive political implications for both political parties: Is extreme partisan gerrymandering unconstitutional?

Here’s CNN’s Ariane de Vogue on the case:

“At issue are maps drawn in Wisconsin after the last census that Democrats say were drawn unconstitutionally to benefit Republicans. They argue the maps represent extreme partisan gerrymander and that they prevent fair and effective representation by diluting voters’ influence and penalizing voters based on their political beliefs.”

The Court’s swing vote – Justice Anthony Kennedy – did little to tip his hand either way, according to de Vogue, a neutrality that will heighten the drama over the case between now and when the Court makes its opinion public early next year.

The decennial line-drawing process has always been a somewhat political endeavor. In most states, state legislators and the governor control the process. When one party controls the state House, state Senate and the governor’s mansion, they have, historically, done everything they can to advantage their side and disadvantage their political opponents.

What’s changed is that technology has transformed what was once a backroom freehand approximation of where the lines should be into a computer-driven, street-by-street parsing of people and votes.

And, with that increased precision has come the strategy – employed by both parties – to pack all of the voters for the other party into the smallest number of districts possible – thereby giving them them a chance to win all of the non-packed districts.

Think of it this way: You are a Republican line-drawer. You have 25 Republican voters and 25 Democratic voters. You need to split those people up into five districts. Would you put five Democrats and five Republicans in each? That would create five swing seats – not ideal for a party trying to maximize its gains. What if instead you put 25 Democrats in one district and zero Republicans in that same district? And then split the remaining 25 Republicans into the remaining four districts? You would lose the one 25-Democrat district for sure. But you’d have a major edge in the other four!

That’s, obviously, an oversimplification. But broadly speaking, it’s what Republicans, who largely controlled the redistricting process after the 2010 census, did in districts across the country. (To be clear: Democrats did the same thing when they had the chance.)

To pack as many of the opposing party into a single district, however,makes for some crazy-looking districts. These are known as gerrymanders – much more on that term here – in the political business. And here are three of the worst.

Maryland’s 3rd district

Here’s how the Almanac of American Politics describes this seat held by Democratic Rep. John Sarbanes: “The 3rd district of Maryland consists of three oddly disjointed pieces of geography that extend from the Inner Harbor area” in Baltimore. The district has been named America’s most gerrymandered by The New Republic.

Pennyslvania’s 7th district

The districts built around Philadelphia and its western suburbs are uniformly ugly. But, the 7th, represented by Rep. Pat Meehan (R), is the worst of the worst. In a feat of understatement, the Almanac says of this seat: “The unconventional shape of the 7th made it one of the most highlighted gerrymanders in post-2010 redistricting.”

Texas’$2 33rd district

This district, currently held by Democratic Rep. Marc Veasey, stretches from southwestern Dallas all the way the northern suburbs of Fort Worth – with a small land bridge in between. The district was drawn by a court to take in much of the Hispanic population in those areas; it is 67% Hispanic and 16% black. (The Texas map is currently in legal limbo with a particular focus on the 27th and 35th districts.)