The Supreme Court case over adding a citizenship question to the census, explained

The Trump administration wants the 2020 census, which will be distributed to all people living in the United States next spring, to ask, “Are you a citizen of the United States?” A group of blue states led by California and New York emphatically do not want a census citizenship question, because they’re worried it will make their residents less likely to return their census forms — and thus hurt their apportionment in Congress after the 2020 census results are tallied.

On Tuesday at 10 am Eastern time, the Supreme Court is hearing oral arguments on who should prevail.

Of course, it’s not that straightforward from the Court’s perspective.

The census lawsuit — arguably the biggest case of this Supreme Court term — raises several levels of legal questions about how government agencies are allowed to make decisions, and how closely the courts (or anyone else) can question the decisions once they’re made.

And the Court doesn’t have much time to figure out the answers. While most lawsuits work through lower courts for years before hitting the Supreme Court, this one was accelerated to the highest level barely three months after a federal judge in New York first ruled that the Trump administration could not ask about citizenship on the 2020 census.

The unusual procedure is justified by the fact that it simply can’t wait. Shortly after the Court’s deadline to issue a ruling on the citizenship question — when the term ends in late June — final census forms will be sent to press. The Supreme Court’s word on the question, even more than usual, will be final.