WESLACO – The source of a controversial question in the census is the immediate focus by the attorneys representing Hidalgo and Cameron counties.

They are fighting the inclusion of the citizenship question and updated Hidalgo County Commissioners Court Tuesday.

The legal team representing Hidalgo and Cameron Counties say where the question comes from and the original intention for that question could prove their argument – that it was done as a "pretext for something else" and that it could violate the constitution.

In a memo dated June 21, the U.S. Department of Commerce Secretary Wilbur Ross, who oversees the Census Bureau, said they inserted the citizenship question after the Department of Justice instructed them to do so on December 12, 2017.

In that same document Secretary Ross stated, "My staff and I consulted with federal governmental components and inquired whether the Department of Justice would support, and if so, would request inclusion of a citizenship question as consistent with and useful for enforcement of the Voting Rights Act."

Rolando Rios, an attorney representing Hidalgo and Cameron Counties in this lawsuit, believes Secretary Ross prompted the DOJ's directive.

"In other words, it's not like they asked us whether they want it in there. Actually, we told them to ask us so that we could then tell the court, 'well, the Justice Department told us,'" Rios explained.

Rios will argue the intention had another "pretext" to include the question – to undercut the Latino vote as census data is used to create congressional districts.

The plaintiffs will also contend that adding this question will affect how many people participate.

The U.S. Census Director Dr. Ron Jarmin admitted that the inclusion of the question will decrease the response rate but only nominally.

"Yes, but we don't expect a one-percent reduction in the response rate," he said during an April Science, Justice, Science Subcommittee House Budget Hearing. 

Dr. Ron Jarmin said the Bureau did estimate how many people would be affected and shared that range with Secretary Ross.

Due to litigation, Dr. Jarmin said he would only say they believe the response rate would decrease by less than one percent if the citizenship question is added.

He believed the majority wouldn't be affected. It would only be felt in certain demographic pockets of the nation.

"So, it just wouldn't have a big impact on the overall response rate. It would be the response rates of subgroups that would matter," said Dr. Jarmin.

Rios believes that if the Census Bureau knows there would be an adverse effect by including the question, it would violate the constitutional requirement to count all who live in the U.S.

Rios' team found the document after requesting the government release internal communications.

He's requested to look at more documents including the Department of Commerce Secretary.

The court ordered the government make them available by next week.

CHANNEL FIVE NEWS will be following that development.