Trump officials tried to add a citizenship question to the 2020 census in a move experts said would benefit Republicans despite initial doubts among some in the administration that it was legal, according to an investigative report released Wednesday by a congressional oversight committee.

The report offers a smoking gun of sorts — a secret memo the committee obtained after a two-year legal battle — showing that a top Trump appointee in the Commerce Department explored apportionment as a reason to include the question.

“The Committee’s investigation has exposed how a group of political appointees sought to use the census to advance an ideological agenda and potentially exclude non-citizens from the apportionment count,” the report released by the House Committee on Oversight and Reform said.

It has long been speculated that the Trump administration wanted the citizenship question in order to exclude people in the country illegally from apportionment numbers.

The report includes several drafts showing how the memo evolved from recognizing that doing so would likely be unconstitutional to coming up with other justifications for adding the citizenship question.

The apportionment process uses state population counts gathered during the once-a-decade census to divide up the number of congressional seats each state gets.

Experts feared a citizenship question would scare off Hispanics and immigrants from participating in the 2020 census, whether they were in the country legally or not. The citizenship question was blocked by the Supreme Court in 2019. In the high court’s decision, Chief Justice John Roberts said the reason the Commerce Department had given for the citizenship question — it was needed for the Justice Department’s enforcement of the Voting Rights Act — appeared to be contrived.

The Commerce Department oversees the Census Bureau, which conducts the count used to determine political power and the distribution of $1.5 trillion in federal funding each year. Then-Commerce Secretary Wilbur Ross testified before the oversight committee that apportionment wasn’t the reason for the citizenship question, even though the Commerce Department memo suggests otherwise, the House report said.

“I have never intentionally misled Congress or intentionally said anything incorrect under oath,” Ross said during a 2019 hearing before the oversight committee.

According to the House committee report, during planning for the citizenship question, an adviser to the Commerce Department reached out to a Republican redistricting expert who had written that using citizen voting-age population instead of the total population for the purpose of redrawing of congressional and legislative districts could be advantageous to Republicans and non-Hispanic whites.

The August 2017 memo prepared by senior political appointee James Uthmeier went to the heart of interactions by the Commerce and Justice departments to come up with a contrived reason for the citizenship question, the House report said.

An initial draft of the memo raised doubts that a citizenship question would be legal since it can only be added to the once-a-decade census if the Commerce Secretary concludes that gathering that information in survey sampling is not feasible. But a later draft removed that concern and added that the Commerce Secretary had the discretion to add a citizenship question for reasons other than apportionment.

An even later draft removed apportionment as an exception to the Commerce Secretary’s discretion and added “there is nothing illegal or unconstitutional about adding a citizenship question.”

An early draft of the memo also noted that using a citizenship data for apportionment was likely unconstitutional and went against 200 years of precedent, but that language also was removed in later drafts.

The Founding Fathers’ “conscious choice” not to exclude people in the U.S. illegally from the count “suggests the Founders did not intend to distinguish between citizens and non-citizens” for apportionment,” Uthmeier wrote in the early draft.

The House report says Uthmeier researched using Voting Rights Act enforcement as a reason for the citizenship question three months before the Justice Department requested it, and hand-delivered his memo with that suggestion to the Justice Department in order to avoid a digital fingerprint.

Uthmeier, who now is chief of staff to Florida Gov. Ron DeSantis, didn’t immediately respond to an email inquiry Wednesday.

In an effort to prevent future attempts at politicizing the census, members of the oversight committee on Wednesday debated a bill introduced by U.S. Rep. Carolyn Maloney, D-N.Y., that would require new questions for the head count to be vetted by Congress, prohibit a Census Bureau director from being fired without cause and limit the number of political appointees at the Census Bureau to three.

Even though many of the Trump administration’s political efforts ultimately failed, some advocates believe they did have an impact, resulting in significantly larger undercounts of most racial and ethnic minorities in the 2020 census compared to the 2010 census.

Republican lawmakers said the bill would make the Census Bureau director unaccountable and limit the ability to add important questions to the census form. They offered an amendment that would add a citizenship question to the next census and exclude people in the U.S. illegally from the apportionment count, claiming their inclusion dilutes the political power of citizens. The Fourteenth Amendment requires that all people in each U.S. state be counted for apportionment.

Committee members recessed Wednesday morning before voting on the bill and amendment.

“What this bill does, it more completely delegates Census Bureau activity to the bureaucracy,” said U.S. Rep. Andy Biggs, R-Ariz. “When you delegate to the bureaucracy, you are taking away the power of the American people.”