At 11:59 p.m. Hawaii time on Thursday, just before 5 a.m. Friday in Chicago, the 2020 census count will end. After that, there will be no more enumerators out in the streets, no more get-out-the-count efforts and no more logging on to my2020census.gov to fill out the questionnaire.

A U.S. Supreme Court ruling earlier this week paved the way for the Trump Administration to end the counting short of an Oct. 31 deadline.

Now questions remain whether this year’s census — which has been challenged by the pandemic, the shortened timeline and chaos at the U.S. Census Bureau — will yield fair and accurate snapshots of communities across the country.

“This will be perhaps the worst census ever; I’m very, very concerned about the accuracy of the count,” said Robert Santos, chief methodologist at the Urban Institute and the incoming president of the American Statistical Association.

Santos said that while no census is perfect — “there are always glitches, always last-minute surprises” — this year’s census will likely yield undercounts in places like Chicago, which have large populations of hard-to-count communities, like immigrants and residents of color.

Meanwhile, “You’re going to have some communities, mostly middle-class, white suburban communities, that are going to be counted really well,” Santos said. “That will [result] in disproportionate funding” in those communities from the federal government.

Santos and a task force of a dozen scientists, researchers and former census bureau directors released a report on the same day as the Supreme Court’s order. The document outlines how the COVID-19 pandemic, legal battles over the timeline, dropped quality control measures,and the politicization of the census could contribute to a headcount that is not fit for use.

The report also calls on the Census Bureau to release data “expeditiously” to carry out an assessment of the quality of the count by outside experts, among other recommendations.

Former U.S. Census Bureau Director John Thompson was part of the task force that wrote the report. Thompson, who worked for the bureau for three decades and helmed the agency from 2013 to 2017, told WBEZ he is “very concerned” the census will not be fair and accurate this year.

Thompson said he was most worried about the data processing stage, in which the agency eliminates duplicate responses, examines computer errors and filters out fraudulent entries. The Census Bureau plans to complete data processing by Dec. 31.

“That process is designed to take five months; they’ll be doing it now in about two and a half months,” he said. “In my opinion, there simply isn’t enough time to do it.”

The U.S. Census Bureau did not immediately respond to a list of questions from WBEZ. In its statement Tuesday announcing the end of the data collection, the agency said it had “accounted for” well over 99.9% of housing units.

According to Thompson, however, “the 99% doesn’t tell you anything about the quality of the census.”

For example, he said the bureau’s completion rate in the 1990 census was “very, very high,” but it still missed about 4% of Black residents and about 5% of Latino residents.

Thompson also said the Trump administration’s interference in the census has contributed to the chaos around the headcount and the distrust of government among the residents that census workers were trying to enumerate in the field.

“The Census Bureau has a longstanding reputation as being an outstanding statistical agency, open, objective, doing important work in a non-political way,” Thompson said. “It’s very sad right now, how the census bureau looks to be so politicized. There’s going to have to be a lot of work to repair public confidence in the science agencies, including the Census Bureau.”

Thompson cited the Trump administration’s installment of political appointees to senior roles in the agency as one of the potential reasons for the bureau’s lack of transparency in recent months.

“I thought it was very inappropriate to put that level of political appointees into the Census Bureau at this time in the process,” he said. “At a minimum, it gives the impression of political manipulation of the census results.”

For weeks, census workers in Chicago have expressed their concerns about the field operations. WBEZ has reported on the issues with the iPhone app enumerators were using to count residents. Many workers also said that they were being rushed to close out their cases, often by cutting corners and dropping quality control measures.

More recently, some census workers have told WBEZ that they have had trouble enumerating high-rises because doormen and management companies would not let them in the building or answer questions after the bureau’s app led multiple workers to the same building.

Census advocates, too, have expressed worries. In particular, they said the reluctance of some residents to participate in the census is due to their distrust of government and the Trump administration’s attempts to exclude undocumented immigrants from the count.

Katrina Herrmann, an enumerator who quit the gig last month, said she understands the census was “stuck between a rock and a hard place with COVID-19 and the Trump administration.” But basic inefficiencies and the rush to wrap up the count will contribute to an undercount, she said, and “it will lead to drastic effects [for] the Chicago community.”

With signs pointing to an inaccurate and less-than-fair census count, Santos, of the Urban Institute, says he expects more legal challenges in coming months.

“As soon as the first counts are submitted to the White House, you can bet that there will be … advocacy groups … just right there submitting their objections, filing suit for an adjustment to the census,” he said.

Santos says statisticians like himself are hoping to offer solutions as well, provided that the Census Bureau releases some necessary data.

“There have been discussions about perhaps identifying areas where there were severe undercounts and coming up with estimates of what they should have been, and then baking those into the population projections that the Census Bureau uses to calibrate their major studies,” Santos said.

As for individuals, he says residents can voice their concerns about the census — which Santos calls “one of the keystones of democracy” — by contacting their local, state and federal representatives.

Esther Yoon-Ji Kang is a reporter for WBEZ’s Race, Class and Communities desk. Follow her on Twitter @estheryjkang.