Michael Wines for the NYT:
On Monday, the Supreme Court heard arguments on a question that goes to the heart of American democracy: Must the government count everyone living in the country, citizens or not, in the census totals that the House of Representatives uses to reallocate its 435 seats among the states?
For more than two centuries, the answer has been “yes.” Both Article 1 of the Constitution and the 14th Amendment require that House seats be allotted according to “the whole number” of persons in each state. That phrase has long been read to include all the nation’s residents, whether American citizens, foreigners admitted here on visas or immigrants with no documents at all. But President Trump signaled in a memorandum this summer that he intended to exclude unauthorized immigrants from the 2020 census totals that he hoped to send to the House next year for use in reapportionment.
Federal courts have ruled in three separate lawsuits that Mr. Trump lacks that authority, saying in one case that the question was not even close. But the Supreme Court will have the final say. Here’s a rundown of some of the basics behind the issue: