The ranking Democrat on the Senate Commerce-Justice-Science Appropriations Subcommittee pushed Monday for an investigation into the decision to cut off census counting a month early, arguing that the administration had meddled in the plan for political gain.

Sen. Jeanne Shaheen, D-N.H., said in a letter Monday to the Commerce Department Office of Inspector General that the Census Bureau may fail to count many people with its new end date of Sept. 30. The bureau had planned to conduct the count from Aug. 11 to Oct. 31, but said last month it would end the count on Sept. 30 to comply with a statutory deadline to complete all its work by Dec. 31.

[Census Bureau to halt counting efforts a month early]

“I believe that this deviation in schedule is driven not by expert opinions of career Census Bureau employees but by external pressure from the White House and the Department of Commerce for perceived political gain,” Shaheen wrote.

The letter cites previous statements by Census Bureau officials that the agency couldn’t complete the process by the existing statutory deadline. For months, career officials have told reporters that the agency could no longer meet that Dec. 31 deadline.

Shaheen wrote that in order to make the new Sept. 30 end-of-count date instead of the planned Oct. 31 date, the agency may cut outreach to hard-to-count households and increase the use of administrative records to finish the count. That may leave many households out of the count, she said.

The national self-response rate stands at more than 63 percent of households, and the Census Bureau intends to reach the majority of the remainder during the in-person counting period. The federal government uses census results to divvy up the 435 House seats as well as guide $1.5 trillion in federal spending annually.

To adapt to pandemic-related delays, the Census Bureau had requested a four-month deadline extension, to April 30, 2021, to finish its work and deliver results to Congress. That would have allowed the agency to continue counting people through Oct. 31.

[Trump’s census memo puts some Republicans in Catch-22]

The House passed that deadline extension as part of its coronavirus relief package. Last month, Senate Republicans proposed legislation that would have provided $448 million for ongoing Census Bureau operations, but didn’t extend the deadlines. That bill hasn’t reached the floor.

In the interim, President Donald Trump signed a memorandum to attempt to exclude undocumented immigrants from apportionment following the 2020 census. That move has faced more than half a dozen federal court challenges seeking to invalidate it as unconstitutional

Challenges to Trump’s effort to exclude undocumented immigrants from the census have cited the shortened count to seek expedited review of their cases.