It is, Justice Ginsburg said, “a case of huge importance.”

“Census Bureau analyses predicted that adding the question would depress the census response rate for noncitizen and Hispanic households, resulting in poorer census data,” she said, adding that evidence in the case undercut Commerce Secretary Wilbur Ross’s explanations for why he had decided to add the question.

Justice Ginsburg’s concluding comments seemed to foreshadow a closely divided case in which she will be on the losing side.

“Speculators about the outcome note that last year, in Trump v. Hawaii, the court upheld the so-called travel ban, in an opinion granting great deference to the executive,” she said, referring to a 5-to-4 decision in which the court’s four liberals dissented. “Respondents in the census case have argued that a ruling in Secretary Ross’s favor would stretch deference beyond the breaking point.”

Justice Ginsburg also touched on other important cases to be decided before the end of the month. One concerns a 40-foot cross honoring soldiers who died in World War I. At the argument in the case, American Legion v. American Humanist Association, No. 17-1717, a majority of the justices seemed inclined to reject the argument that the cross was an unconstitutional endorsement of religion.

On Friday, Justice Ginsburg called the cross a “towering monument” and quoted with seeming approval from an appeals court decision requiring its removal. “The Latin cross, the majority reasoned, is not a generic symbol of death,” she said, “it is the ‘pre-eminent symbol of Christianity,’ the ‘symbol of the death of Jesus Christ.’”

In that case, too, it would not be surprising if Justice Ginsburg found herself in dissent.

There are two other pending decisions “very high on the most-watched-cases list,” Justice Ginsburg said, referring to challenges to voting maps in North Carolina and Maryland that were designed to amplify the power of the political party in control of the state legislature.

Justice Ginsburg explained the basic problem. “Given modern technology,” she said, “a state legislature can create a congressional delegation dramatically out of proportion to the actual overall vote count. In North Carolina, for example, in the 2016 election, Republicans won 53 percent of the statewide vote, yet they won 10 of the 13 congressional seats.”