For months, liberal groups have collected evidence that the Trump administration’s decision to add a citizenship question to the 2020 Census was intended to benefit white Republicans.

There was a judicial opinion, released in January by a U.S. district judge in New York, which cited evidence that Commerce Secretary Wilbur Ross ignored experts who warned that the question would lead to an undercount of minority voters. In March, a federal judge found the same thing.

And just last month, the daughter of the late Thomas Hofeller, a Republican redistricting strategist, turned over evidence showing that her father lobbied the Trump administration for a citizenship question because he believed it would benefit Republicans and whites. As The Washington Post’s Tara Bahrampour and Robert Barnes wrote:

Hofeller “played a significant role in orchestrating the addition of the citizenship question to the 2020 Decennial Census in order to create a structural electoral advantage for, in his own words, ‘Republicans and Non-Hispanic Whites,’ ” plaintiffs’ lawyers challenging the question wrote in a letter Thursday morning to U.S. District Judge Jesse M. Furman, one of three federal judges who ruled against the question this year. The lawyers also argued that Trump administration officials purposely obscured Hofeller’s role in court proceedings.

The files show that Hofeller concluded in a 2015 study that adding a citizenship question to the 2020 Census “would clearly be a disadvantage to the Democrats” and benefit white Republicans in redistricting. Hofeller then pushed the idea with the Trump administration in 2017, according to the lawyers’ letter to Furman.

The Justice Department has pushed back, saying the allegation that it hid the government’s motives for adding the citizenship question are “frivolous” and an attempt to “derail” a Supreme Court ruling on the matter, expected by the end of June.

But Rep. Joaquin Castro (D-Tex.), chairman of the congressional Hispanic Caucus, said the citizenship question would harm many individuals living in the United States and make it harder for the country to meet their needs.

“It’s an intimidation play,” Castro told The Fix. “They are trying to get communities who have not been comfortable being asked a few hundred questions in the census to be even more fearful of somebody from the government knocking on their door asking questions.”

Castro said the caucus is urging community advocates to join “the chorus of voices” opposing the Trump administration’s efforts.

“We’ve been supportive of the lawsuit to get rid of the citizenship question, and we’ll be bringing Trump administration officials in front of us to explain the thinking and to explain whether there was any coordination about how they came up with their citizenship question,” he added.

Groups advocating for Latino communities have also been pushing back, warning that if communities are undercounted, projects and programs will be underfunded.

“This is an assault against the Latino community. Hispanics — 8 out of 10 of whom are United States citizens, by the way — but it’s bigger than that,” Clarissa Martínez de Castro, a deputy vice president at UnidosUS, a national nonprofit advocating for socioeconomic issues for Latinos, told The Fix. “It’s not just an assault against Hispanics. It’s actually going to undermine communities nationwide where Latinos and others who stand to be undercounted reside. It’s about taking away resources from those communities.”

The NAACP has also pushed back, filing a lawsuit arguing that people of color, including black Americans, will be drastically undercounted by the 2020 Census because the government is inadequately prepared, a violation of the legal obligation to conduct a full and fair count. The NAACP and other groups have also urged the Supreme Court to reject the question, arguing that it will harm communities of color.

In the event that the question does make it onto the census questionnaire, Martínez de Castro said UnidosUS will focus on making sure people are counted so that they can get the services they need.

"We’ll focus on intensifying our work with our affiliate network of nearly 300 community organizations, and national and local partners, to give our communities the information and tools they need to get counted, and hold our government accountable for meeting its constitutional mandate to achieve an accurate count and respect the integrity of that information,” she said.

The Trump administration’s efforts to add a citizenship question will probably turn off voters of color, making it even harder for Republicans to win them over in future elections.