An internal Census Bureau document sent to members of Congress and obtained by NBC News warned that the new truncated deadline set by the agency's director last month has the potential to undermine the integrity of the count and lead to "serious errors."
The document was sent to the House Oversight Committee, which has been probing the Census for several years since its failed attempt to add a citizenship question to the decennial.
Census Director Steve Dillingham said last month that the agency would end all of its counting efforts on Sept. 30, a month sooner than previously expected. Some areas, including San Diego, will see in-person operations end even sooner.
The document warns that the "highly compressed" timeline, as well as limits to activities such as door-knocking and data review, will lead to less accurate results.
"A compressed review period creates risk for serious errors not being discovered in the data— thereby significantly decreasing data quality," the document said. It added, "Additionally, serious errors discovered in the data may not be fixed— due to lack of time to research and understand the root cause or to re-run and re-review one or multiple state files."
The document appears to be a presentation for Commerce Secretary Wilbur Ross, who oversees the agency, dated Aug. 3, 2020 and marked "Not for Public Distribution." Oversight Committee Chairwoman Rep. Carolyn Maloney, D-N.Y., wrote in a letter to congressional leaders on Wednesday that she obtained the document from a "source," rather than from one of the agency's leaders.
The agency will also have far less time and resources to review the data than in previous years, the document said. This year, the document said, the bureau will process data in only 92 days. The 1990 Census used 140 days, the 2000 Census used 185 days and the 2010 Census used 147 days.
The document is the latest indication of the issues plaguing the census to fulfill its constitutional mandate to count all persons living in the U.S., which determines Congressional seats, federal aid sent to states, among many other areas. Roughly 65 percent of households have so far self-responded to the census, according to the agency, with an additional 19 percent counted by in-person efforts.
The move has raised fears among various civil rights groups, researchers and other experts who fear that a significant portion of the population, such as minorities and immigrants, could be left of out the tally.
"This is really an insidious ploy to have cities that have large immigrant communities in particular to lose congressional representation and to have that representation moved to red Republican areas," New York City Census Director Julie Menin told NBC News last month. "That's what this whole battle is about."
The agency requested bipartisan action this past spring to extend its mandated Dec. 31 deadline for turning in data to federal and state governments until April 30, 2021.
Maloney in her letter on Wednesday urged Democratic and Republican leaders in the House and Senate to extend the deadline to ensure that that the census is accurate. House Democrats passed a bill in May to push the deadline due to the coronavirus pandemic, but legislation is stalled in the GOP-controlled Senate.
"In light of this new internal document and the additional information we have obtained, it is more urgent than ever that the Senate act," Maloney said in the letter on Wednesday. "Congress has a solemn responsibility under the Constitution to help ensure an accurate and complete count, and there is bipartisan support in the Senate for extending these deadlines."