Reuters with an early report from today’s oral argument:

During an extended, 80-minute argument session, the court’s liberal justices voiced skepticism over the need for the question to enforce a federal voting rights law – the administration’s stated justification.
Lower courts have blocked the question, ruling that the administration violated federal law and the U.S. Constitution in seeking to include it on the census form.
The court has a 5-4 conservative majority, and conservative justices signaled support toward the administration’s stance.
Chief Justice John Roberts challenged New York Solicitor General Barbara Underwood, whose state sued the administration over the plan to add the question, saying citizenship is critical information for enforcing the Voting Rights Act.

Experts in fact have said that the citizenship question is unnecessary for enforcement of the Voting Rights Act. And it is undisputed in the record in these cases that the VRA was just a pretext for Secretary Ross to add the question to the census (likely it was for political reasons). He had to reach out to DOJ to get DOJ to request the citizenship question.

As I wrote at Slate a few weeks ago:

So too are political lines apparent in the census case. The U.S. government is defending the inclusion of a question about citizenship for the first time since the 1950 census as needed to provide accurate demographic information to the Department of Justice to help it protect Latinos in Voting Rights Act lawsuits. But two courts have already found that Commerce Secretary Wilbur Ross insisted on including the citizenship question for undisclosed reasons, and that the DOJ voting rights claim was a mere pretext. Republicans have again lined up in favor of including the question, which Democrats oppose as likely to inhibit a complete and accurate count of all persons in the United States, leading to lower representation in Democratic-leaning areas and fewer federal resources based on population….

The census case is jurisprudentially easier. The Commerce Department’s decision to include the citizenship question is a textbook example of arbitrary and capricious action in violation of the Administrative Procedure Act. The only justification that the department has offered for including the question—helping DOJ help Latinos in voting rights cases—has indisputably been found to be a pretext. Whether Ross was actually motivated by partisan considerations is beside the point. And yet conservative Justices Neil Gorsuch and Clarence Thomas were so put off by this lawsuit that they were willing to stop the trial in the case even before judgment. The court’s other conservatives too might be swayed by the strong political valence of the case.