You can find the complaint here. The main argument in the case is that plaintiffs engaged in a racial gerrymander by making race the predominant factor in drawing district lines without s compelling reason to to so. The primary allegations concern what the mapmaker for the Legislature said about protecting Latino voting power in the new district lines, something that the state would be required to do to to comply with Section 2 of the Voting Rights Act.

If partisanship, preserving communities of interest or other factors predominated when the Legislature drew the lines enacted via Proposition 50, then the case would fail on the first prong. Seems like this was a very partisan process, so there’s a good chance the case would fail on this prong. If we get to the second prong, the state could try to defend by saying the districts were drawn race consciously to comply with the Voting Rights Act.

There is also a brief set of claims in here that the Legislature drew lines to intentionally discriminate against Latinos. That claim is supported by no real evidence and I don’t expect it to go anywhere.

Plaintiffs will likely seek a preliminary injunction and have asked for a three-judge court. They will likely want a preliminary injunction hearing quickly. It may not happen quickly, and as we get closer to the election, the Purcell Principle, which has been applied to similar challenges in Louisiana and Alabama, tells courts not to make changes to districts in the period close to the election. Although applying Purcell typically has benefitted Republicans could benefit Democrats in this instance.

If the district court denies the injunction, plaintiffs could try to get emergency relief from the Supreme Court.