New evidence in a legal challenge to a citizenship question on the 2020 census reveals the Trump administration hid its recommendation by a political strategist seeking to strengthen the GOP’s political heft in Democratic strongholds, an immigrant rights group said Thursday.

The New York Immigration Coalition, which sued over the matter, wrote in a letter to U.S. District Judge Jesse Furman that documents show Thomas Hofeller, a former Republican political strategist and redistricting expert, “played a significant role in orchestrating the addition of the citizenship question” to give Republicans and non-Hispanic whites an electoral advantage.