The term “partisan gerrymandering” is a mouthful. It makes a lot of people’s eyes glaze over.

But it’s a huge deal, and today’s Supreme Court decision about it in the case of Rucho v. Common Cause is like a nuclear bomb that will have devastating impacts on American democracy. It was another 5-4 vote along ideological lines, with conservatives in the majority.

Gerrymandering is the practice of drawing electoral districts to advantage whoever’s doing the drawing. It’s been going on for centuries—it’s named after Eldridge Gerry, who died in 1814—but today’s gerrymandering is not Eldridge Gerry’s gerrymandering.

Thanks to “big data”, political operatives can slice and dice district lines on a house-by-house basis. They know so much about all of us, as we learned from the Cambridge Analytica-Facebook scandal in 2016, that they can predict with shocking accuracy how we’re going to vote.

And it works.

In Wisconsin, Republicans used big data methodologies to create the most slanted electoral map in memory. It gave Republicans 60 percent of the seats in the state assembly despite winning only 47 percent of the vote.

In Pennsylvania, 44 percent of Pennsylvania’s voters are Democrats—but only 33 percent of its congressional representatives.

And in North Carolina – the site of one of today’s two cases – thanks to a GOP-engineered gerrymander, Republican candidates won nine of the state’s 13 seats in the House of Representatives in 2012, although they received only 49 percent of the statewide vote. In 2014, Republican candidates increased their total to 10 of the 13 seats, with 55 percent of the vote.

Nationally, despite winning fewer than half of all votes for the House in 2016, Republicans still held an advantage of 241 to 194 House seats, thanks to the 2010 REDMAP project to flip state legislatures and gerrymander electoral districts.

Gerrymandering also has direct, concrete effects. The new documentary Slay the Dragon convincingly shows how the Flint water crisis was a direct result of Michigan’s gerrymandered statehouse, as protected Republican lawmakers overturned a massively popular referendum and installed “emergency managers” in cities like Flint. One such manager ordered Flint to change its water source, leading to massive lead poisoning in 2014.

The film also persuasively links gerrymandered legislatures to Wisconsin’s suppressive voter ID law and North Carolina’s anti-trans “bathroom bills,” neither of which were supported by a majority of the states’ populations. The film is a must-see for anyone concerned about our democracy.

Yet today, the Supreme Court said all of this is perfectly fine. Or at least, that the courts aren’t going to do anything about it.

“ The partisan gerrymanders in these cases deprived citizens of the most fundamental of their constitutional rights. ” — Justice Kagan

According to Chief Justice John Roberts, gerrymandering is a “political question” not a constitutional or legal one. Love it or hate it, Roberts says, the way to address gerrymandering is by voting for representatives who oppose it, not by going to court.

But wait a minute.

How can you vote for anti-gerrymandering politicians when your vote has already been diminished by gerrymandering? If you and every other Democrat (or Republican – the other of today’s cases involved Democratic gerrymandering in Maryland) has been packed into one district by a devious gerrymander, you can’t affect the political process they way you could’ve if the district lines were fair.

The political process can’t fix itself: it’s what’s broken.

“The partisan gerrymanders in these cases,” wrote Justice Kagan in an unusually strong dissent, “deprived citizens of the most fundamental of their constitutional rights: the rights to participate equally in the political process, to join with others to advance political beliefs, and to choose their political representatives. In so doing, the partisan gerrymanders here debased and dishonored our democracy, turning upside-down the core American idea that all governmental power derives from the people.”

“Is that how American democracy is supposed to work?” asked Justice Kagan rhetorically. “I have yet to meet the person who thinks so.”

Vanita Gupta, president of the Leadership Conference on Civil and Human Rights, called today’s decision “a huge disappointment.” She said it will “continue this process of politicians choosing their voters rather than voters choosing their politicians.”

What happens now? Bad news.

First, a new era of extreme gerrymandering. Republicans, thus far, have an edge on Democrats when it comes to rigging electoral maps, but surely Democrats are going to close the gap. The result, at least in the short term, will surely be more and more extreme maps rigged to favor the majority party in the state legislature.

Moreover, as Justice Kagan noted in her dissent, we ain’t seen nothin’ yet. With advances in machine learning, even today’s advanced data analysis tools will seem rudimentary a decade from now. Things are going to get worse before they get better.

Second, as Slay the Dragon showed, it’s extraordinarily difficult to fight back against gerrymandering, because the incumbents who drew the districts will, naturally, do anything to preserve their advantage. In Slay the Dragon, scrappy activists in Michigan were suddenly avalanched by gigantic dark-money-funded PR campaigns that distorted the facts and maligned the activists themselves.

Third, right now, voting rights are barely on the national priority. Gerrymandering is only part of the problem; so are voter suppression tactics like voter ID laws, closing voting places, disenfranchising felons, and purging voter rolls.

In addition to the radical disproportions noted above, these tactics may have swung the 2016 presidential election. In Wisconsin, Trump’s margin of factory was 27,257. But there were 300,000 registered voters without ID who were prevented from voting. How many would’ve voted for Clinton? We’ll never know. But in Democrat-heavy Milwaukee, 41,000 fewer people voted in 2016 than 2012.

Yet Mother Jones columnist Ari Berman, who wrote a brilliant book on the subject, pointed out in a tweet this week that “there were 25 presidential debates in 2016 but not a single question about gutting of Voting Rights Act or attack on voting rights. That can’t happen again. Issues like voter suppression, gerrymandering & the census need to be front and center in 2020.”

And so far in the 2020 debates, we’re 0 for 1. Not a single question was asked on voting rights or voter suppression in the first Democratic presidential debate.

That has to change, obviously, especially now that the judicial branch is not going to defend free and fair elections. “Partisan gerrymandering” has to stop being a tongue-twister and start being known for what it is: one of the main reasons our country’s government does not represent its people.