The Trump administration's plan to include a citizenship question on the 2020 census encountered some skepticism Tuesday from the U.S. Supreme Court as the justices probed the reasons why the U.S. Commerce Department added the question and its potential impact on the census's accuracy.

After an extended argument, however, it appeared the Supreme Court could divide along ideological lines on what is the most significant Trump policy fight to come before them since they ruled 5-4 last term to uphold the administration's immigration travel ban.

U.S. Solicitor General Noel Francisco argued the issue of adding the citizenship question was not subject to judicial review because Congress had committed such issues to the discretion of the secretary of the Commerce Department.

Francisco warned that if the high court did review the issue, the justices would find themselves evaluating every question placed on the census for its impact on the count. He also said the Commerce Secretary Wilbur Ross acted reasonably in choosing to put the citizenship question on the census short form when faced with uncertainty about the accuracy of alternatives recommended by the Census Bureau staff.

But Justice Elena Kagan told Francisco “there's a bottom line conclusion” from the Census Bureau that putting the question on the census would result in poorer data than the bureau's proposed models.

“The secretary can deviate [from the bureau's recommendation] but he needs reasons to do that,” Kagan said. “I searched the [lower court] record and I don't see them.” She remained dissatisfied with Francisco's list of reasons and added, “Your briefs are extremely well done. A lot of your arguments don't appear in the secretary's reasons.”

Justices Neil Gorsuch and Brett Kavanaugh pushed back against arguments made by New York Solicitor General Barbara Underwood and Douglas Letter, general counsel to the House of Representatives by noting that the United Nations recommends and a number of countries do include a citizenship question on their census forms. Gorsuch also noted that for a period of years, until 1950, the U.S. census asked a citizenship question.

“What do we do with that history and the evidence of practices around the world?” Gorsuch asked both lawyers.

Judge Neil Gorsuch testifies before the Senate Judiciary Committee during the second day of his confirmation hearing to replace the late Justice Antonin Scalia at the U.S. Supreme Court. March 21, 2017.

Underwood said the UN guidance cautions nations to be careful that the question does not undermine the enumeration. “It is useful information for a country to have, but the question is whether that information should be collected on a form whose principal function is to count the population,” she said.

During Tuesday's arguments—expanded from the usual 60 minutes to 80 minutes—four lawyers took their turn before the justices: Francisco for the Trump administration's Commerce Department; Underwood for New York and its co-challengers; the ACLU's Dale Ho for the New York Immigration Coalition, and Letter, who made his second-ever argument at the high court.

The justices have been asked to decide whether the decision to add a citizenship question violated the Constitution's enumeration clause; whether the decision was arbitrary and capricious and in violation of the Administrative Procedure Act, which sets the ground rules for changes in policy by federal agencies, and whether a district court can order discovery outside the administrative record to compel testimony of high-ranking agency officials.

The justices did not spend time on the constitutional issue, instead, focusing their questions on the reasonableness of the secretary's move under the Administrative Procedure Act.

The high court's decision is needed by the end of June in order to meet the deadline for printing the 2020 census.

The case stems from Ross' announcement, in a March 2018 memo, that the Census Bureau would add a citizenship question to the 2020 short-form census questionnaire. He claimed the U.S. Justice Department asked for the question in order to help to enforce the Voting Rights Act.

Wilbur Ross, U.S. commerce secretary. Photo: Andrew Harrer/Bloomberg

New York, other states and cities, civil rights groups and nonprofit organizations sued to block Ross's action. They claimed that a citizenship question would result in an undercount—by some experts an estimated 6.5 million people—especially among Hispanic, immigrant and minority communities who fear deportation of family members and friends. Career Commerce officials have said the decision to add a question would cause an undercount.

An undercount, the plaintiffs contend, would result in a loss of billions of dollars of federal funds and affect reapportionment of congressional seats. Ross' move, the challengers argue, violated the Constitution's enumeration clause and the Census Act, and was arbitrary and capricious under the Administrative Procedure Act.

Seven lawsuits were filed in four federal district courts challenging the secretary's announced plan. Three trial judges have ruled that Ross' reason for adding the citizenship question—which he stated under oath to a congressional committee—was pretextual and that he had pressured the Justice Department to supply a rationale long after he had decided to add the question. All three agreed the secretary violated the Administration Procedure Act and the Census Act, and two of the three concluded he violated the enumeration clause as well.

U.S. District Judge Jesse Furman of the Southern District of New York in January ruled that Ross had committed a “veritable smorgasbord” of Administrative Procedure Act violations and had “alternately ignored, cherry-picked, or badly misconstrued the evidence in the record before him.”

From 1820 to 1950, every decennial census, except one, contained a citizenship question. Since 1950, the short form questionnaire—which will be the only form used in 2020 to take an “actual Enumeration”—has not included a question about citizenship or birthplace.

The Census Bureau has used the annual American Community Survey, which goes to about two percent of households, to collect demographic information about the population. A long-form census questionnaire, used from 1960 to 2000 and distributed with the short form, has, like the ACS survey, collected demographic information, including a citizenship question.

Nearly 50 amicus briefs have been filed by a wide range of states, local governments, businesses, historians, statistical organizations and others, with most supporting opponents of the citizenship question.

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