I was involved in a gerrymandering case in the 1990s. The group that brought me in was challenging the Illinois congressional map, which had been drawn by Democrats. It was, and is, atrocious. Back then, the map was a deal between the white Democrats who wanted to hold some white seats that extended into the suburbs, and some black Democrats who wanted incumbent protection.
Back then, the Democrats were the ones across the country who were protecting racial gerrymanders because they wanted to ensure that any area with a substantial black population was never represented by a Republican. They drew the districts in Illinois to ensure as many black-majority districts as possible (and one Hispanic-majority district). The districts were completely convoluted. They made arguments that the Voting Rights Act actually required racial gerrymanders.
Our side challenged the districts. The other side, defending the gerrymander, was led by the Mexican-American Legal Defense Fund, and they brought in the Clinton Administration Justice Department as defendant-intervenors. That's right -- the primary defender of gerrymanders was the Clinton Administration. They were involved in similar suits, making similar claims, across the country.
Demographics have shifted a bit since then, and now we have more Republican gerrymanders than Democrat ones. But make no mistake -- the original convoluted maps were all Democrat, and virtually all Supreme Court gerrymandering-related precedent during the era came as a result of Democrat defense of the maps.
So don't try to claim that Democrats "play clean and fair". That's rubbish. They created this problem, and only now are shifting their views of gerrymandering because it is no longer working to their benefit. They, like most politicians, are opportunists.
Disclosure: I'm now the chairman of the Chicago Republican Party.