The Supreme Court is set to hear arguments over the Trump administration’s plan to ask about citizenship on the 2020 census, a question that could affect how many seats states have in the House of Representatives and their share of federal dollars over the next 10 years.

Three federal courts have blocked the Commerce Department from adding the citizenship question. Those courts have ruled that Commerce Secretary Wilbur Ross violated federal law in the way he went about trying to include the question for the first time since 1950. They found that millions of Hispanics, who tend to vote for Democrats, and immigrants would go uncounted.

The lower court judges dismissed Ross’ contention that the question, and the detailed information it would produce on where eligible voters live, is needed to aid in the enforcement of the federal Voting Rights Act.

Two of the three judges also ruled that asking if people are citizens would violate the provision of the Constitution that calls for a count of the population, regardless of citizenship status, every 10 years.

Census Bureau experts have concluded that the census would produce a more accurate picture of the U.S. population without a citizenship question because people might be reluctant to say if they or others in their households are not citizens. Federal law requires people to complete the census accurately and fully.

The Supreme Court is hearing the case on a tight timeframe, even though no federal appeals court has yet to weigh in. A decision is expected by late June, in time to print census forms for the April 2020 population count.

The administration argues that the commerce secretary has wide discretion in designing the census questionnaire and that courts should not be second-guessing his action. States, cities and rights groups that sued over the issue don’t even have the right to go into federal court, the administration says. It also says the question is plainly constitutional because it has been asked on many past censuses and continues to be used on smaller, annual population surveys.

Opponents of the question obtained documents and testimony that showed Ross had begun pressing for a citizenship question soon after he became secretary in 2017, and that he had consulted Steve Bannon, who had been President Donald Trump’s top political adviser, and then-Kansas Secretary of State Kris Kobach. Emails showed that Ross himself had invited the Justice Department request to add the citizenship question.

The Supreme Court has sent somewhat conflicting signals about how it might resolve the case. The justices allowed the first trial, in New York, to take place, over the administration’s objection. Justices Samuel Alito, Neil Gorsuch and Clarence Thomas would have halted the trial.

The high court also prevented the challengers from taking sworn testimony from Ross, though it allowed the questioning of other officials.

(AP)