The report focuses on Rep. Jerry McNerney, the a Bay Area Democrat who seemed to be vulnerable in the redistricting process. McNerney hired Redistricting Partners, a consulting firm that, according to ProPublica, drew up maps for a mysterious advocacy group called OneSanJoaquin.
The group's stated aim was to keep the San Joaquin Valley in one district, but its maps had the effect of creating a Democratic-leaning seat. The group encouraged people to testify before the commission and to write letters supporting OneSanJoaquin's maps. Once the commission created the new San Joaquin district, McNerney announced he would move there and run for re-election.
The story also discusses Rep. Judy Chu, a San Gabriel Valley Democrat. The story highlights the role of the Asian American Education Institute in lobbying for a district that would favor Chu's re-election. The institute, which claimed to speak for the San Gabriel Valley Asian community, had ties to Chu's political team, and also hired Redistricting Partners.
ProPublica suggests that the citizens' commission was overmatched by Democratic operatives, because it had a limited budget and little time to go hunting for hidden agendas. It also says that Republicans didn't wage the same sort of lobbying campaign, which may help explain why they got hammered.
Republicans have filed a federal lawsuit to overturn the Congressional map.
Update: Republicans are claiming vindication, and calling for a thorough investigation.
Democratic Party Chair John Burton has a somewhat different take. In an interview with the S.F. Chronicle, Burton called the report "complete bullshit" and "an absolute fucking fabrication."
State Sen. Ted Lieu (D-Torrance) delivers a less profane response on Twitter: