The question facing House Democrats as they met to contemplate the state’s new realities was delicate: How could they influence an avowedly nonpartisan process? Alexis Marks, a House aide who invited members to the meeting, warned the representatives that secrecy was paramount. “Never say anything AT ALL about redistricting — no speculation, no predictions, NOTHING,” Marks wrote in an email. “Anything can come back to haunt you.”

In the weeks that followed, party leaders came up with a plan. Working with the Democratic Congressional Campaign Committee — a national arm of the party that provides money and support to Democratic candidates — members were told to begin “strategizing about potential future district lines,” according to another email.

The citizens’ commission had pledged to create districts based on testimony from the communities themselves, not from parties or statewide political players. To get around that, Democrats surreptitiously enlisted local voters, elected officials, labor unions and community groups to testify in support of configurations that coincided with the party’s interests.

When they appeared before the commission, those groups identified themselves as ordinary Californians and did not disclose their ties to the party. One woman who purported to represent the Asian community of the San Gabriel Valley was actually a lobbyist who grew up in rural Idaho, and lives in Sacramento.