WASHINGTON -- Supreme Court justices on Tuesday appeared ready to uphold the Trump administration's attempt to add a citizenship question to the 2020 census.
The justices were sharply split along ideological lines with the court's conservatives clearly on the side of deferring to the administration.
By the end of the argument, it sounded as though the court would hand down a 5-4 decision in support of the Trump administration.
Debates over the census are usually reserved for demographers and statisticians, but the dispute over the citizenship question is one of high politics.
Lawyers for California and other blue states with large numbers of immigrants fear that millions of households will refuse to fill out the census forms if the citizen question is included out of concern that the confidential information will be shared with immigration agencies.
The states worry a potential undercount in the once-a-decade tally will cost billions of dollars in federal funds as well as a loss in political clout.
The seats in the House of Representatives and in state legislatures are allocated based on census data. And the Constitution says "representatives shall be apportioned ... counting the whole number of persons in each state." This has been understood to mean that all residents are counted, regardless of whether they are citizens.
But Commerce Secretary Wilbur Ross announced last year that he had decided to add a citizenship question for all households for the first time since 1950. Since then, the government has used surveys or a "long form" given to a sample to gather data on the growing population of foreign-born residents and naturalized citizens.
Ross said he chose to add the new question to improve compliance with the Voting Rights Act. But judges dismissed this as far-fetched.
Federal district court judges in New York, San Francisco and Baltimore ruled that Ross' decision violated the Administration Procedures Act because it conflicted with the views of census experts inside and outside the government.