Thomas Hofeller

After his death, Hofeller's daughter, Stephanie Hofeller, made available computer hard drives that had been in her father's possession.[6] Files on the hard drives showed that he played a key part in the decision of the Trump administration to add a citizenship question to the 2020 census, a decision that was challenged in the federal courts in the case Department of Commerce v. New York. Hofeller had conducted a study in 2015 which found that adding such a question would make it possible to draw district boundaries that "would be advantageous to Republicans and non-Hispanic whites." Hofeller himself wrote the portion of the Department of Justice letter used to justify why the Trump administration had made this decision. The letter claimed that adding the citizenship question was necessary to enforce the 1965 Voting Rights Act.[2] The New York Times described the files as "the most explicit evidence to date that the Trump administration added the question to the 2020 United States Census to advance Republican Party interests."[2]

In May 2019, the plaintiffs suing over the 2020 United States Census citizenship question cited the 2015 Hofeller analysis and other documents in a motion for sanctions, saying "many striking similarities" existed between the unpublished Hofeller analysis and the United States Department of Commerce's decision to seek a citizenship question on the Census.[2] The federal government, in response, said that the Hofeller study "played no role in the department's December 2017 request" for a citizenship question on the Census.[2] In June 2019, the United States Court of Appeals for the Fourth Circuit, citing the Hofeller document, remanded the case to the U.S. district court to determine whether the Trump administration's stated rationale for adding a citizenship question to the 2020 census was in fact a pretext for a discriminatory purpose (the dilution of voting power of Hispanic voters in order to advantage Republicans and non-Hispanic whites).[8]

On July 5, 2019, Judge George J. Hazel of the United States District Court for the District of Maryland, which is part of the Fourth Circuit Court of Appeals, approved the commencement of discovery into the Hofeller files.

The New Yorker was the first media outlet to obtain at least seventy thousand files and several years of emails that were saved by Hofeller. David Daley wrote that the files "...mostly pertain to Hofeller’s work in North Carolina, where he drew—and defended in court—the state’s legislative and congressional maps multiple times, after judges ruled them to be either unconstitutionally partisan or racial gerrymanders."[5] On Sept. 3, 2019, in the case of Common Cause v. Lewis, a North Carolina court struck down the state's legislative maps as a partisan gerrymander in violation of the state constitution. Mark Joseph Stern wrote in Slate, "The court had unprecedented access to the gerrymandering process thanks to the Hofeller files..."[9] The court cited from Hofeller's files that "metadata on maps of state legislative districts showed they were almost completely drawn months before Republican legislative leaders publicly adopted the standards for drawing them." The three-judge panel also cited his files "in concluding that he had used racial statistics to shape his maps despite public claims to the contrary."[10] Jowei Chen, a professor of Political Science at the University of Michigan, had testified in July 2019 that he had found that Hofeller had manually entered "%18_ap_blk" into nearly every draft of his mapping software when he mapped North Carolina's districts. The formula "%18_ap_blk" shows the number of African American citizens of voting age in each district.[11]

In November 2019, a court ruled that Hofeller's files were no longer considered confidential as they address political activities in other states, affecting redistricting and the national census, and could be used in other suspected cases of gerrymandering.[12] The files covered Hofeller's work on political maps in Arizona, Florida, Maryland, Mississippi, Missouri, Ohio, Tennessee and Virginia, along with Nassau County in New York and Galveston and Nueces Counties in Texas.[13]

Hofeller's daughter, Stephanie, several weeks after announcing her intentions on Twitter,[14] published copies of her father's files on January 5, 2020.[15]

Encouraging others to "mirror" the files and/or create and seed torrents as quickly as possible, Stephanie was able to keep her shared Google Drive available for just over a week before overwhelming traffic brought down the drive. Nevertheless, the plan to distribute the files was successful.

A list of co-locations, as well as updates on continuing efforts to process the files into a searchable database, can be found at the site Hofeller continues to maintain: thehofellerfiles.org