WASHINGTON (Reuters) - The U.S. Supreme Court on Friday broadened the scope of what it will consider in resolving the legal fight over the contentious decision by President Donald Trump’s administration to add a citizenship question to the 2020 census, agreeing also to decide whether the move violated the U.S. Constitution.

FILE PHOTO: U.S. Commerce Secretary Wilbur Ross testifies before a House Oversight and Reform Committee hearing on oversight of the Commerce Department, in Washington, U.S., March 14, 2019. REUTERS/Mary F. Calvert/File Photo

In the aftermath of a March 6 ruling by a federal judge in California, the high court said it will decide whether Commerce Secretary Wilbur Ross ran afoul of the Constitution’s so-called Enumeration Clause, which sets out the terms under which people should be counted in the census, when he added the citizenship question in March 2018.

Various states including New York and California as well as civil rights groups have challenged the question in court. They have said that asking people about their citizenship could scare immigrants and Latinos into abstaining from the census, disproportionately affecting Democratic-leaning states.

Two judges have blocked the addition of the question. The Supreme Court previously agreed to resolve whether adding the question violated a federal law called the Administrative Procedure Act, as a federal judge in New York ruled on Jan. 15.

The Supreme Court, which has a 5-4 conservative majority, is set to hear oral arguments on April 23, with a ruling due by the end of June.

The U.S. Constitution mandates a census every 10 years. The official population count is used in the allocation of seats in the U.S. House of Representatives and the distribution of billions of dollars in federal funds. There has not been a census question about citizenship status since 1950.

Opponents have accused the administration of trying to engineer an undercount of the true population and diminish the electoral representation of Democratic-leaning communities in Congress, benefiting Trump’s fellow Republicans. Non-citizens comprise an estimated 7 percent of people living in the United States.

The Supreme court last month granted the administration’s request to hear its appeal of Manhattan-based U.S. District Judge Jesse Furman’s January ruling even before a lower appeals court had considered the matter.

San Francisco-based U.S. District Judge Richard Seeborg this month found in a suit brought by the state of California not only that the administration failed to follow the correct process under federal law in adding the question but also that the move violated the Enumeration Clause, an issue not decided by Furman.

“The evidence admitted in the trial of these actions demonstrates that a significant differential undercount, particularly impacting noncitizen and Latino communities, will result from the inclusion of a citizenship question on the 2020 Census,” Seeborg wrote.

By taking up both questions, the Supreme Court ensures that all legal issues relating to the census will be resolved quickly. Time is of the essence, as the official census forms are due to be printed in the coming months.

Ross defended the administration’s decision to add the question in congressional testimony on Thursday, but faced sharp criticism from Democratic lawmakers.

When announcing that the citizenship question would be added, Ross said the Justice Department had requested the data to help enforce the Voting Rights Act, which protects eligible voters from discrimination. Only U.S. citizens can vote in federal elections.

Democrats call the citizenship question part of a broader Republican effort at the federal and state level, also including voter-suppression measures and redrawing of electoral districts, to diminish the voting power of areas and groups that typically back Democratic candidates, including immigrants, Latinos and African-Americans. Republicans reject the accusation.