In July, President Trump ordered that the 2020 census tabulate unlawful immigrants separately from other residents so that he would have the discretion to exclude unlawful immigrants from being counted for the basis of determining the apportionment of House seats for each state. Several states challenged that order, and a three-judge district court panel enjoined operation of the order due to its perceived chilling effect on unlawful immigrants to respond to the census, and would not reflect “the whole number of persons in each State” as required by law.
In Trump v. New York, the Court, in a 6-3 per curiam ruling, held that the case was “riddled with contingencies and speculation” that rendered it premature for any kind of judicial resolution, since the census results had not yet been tabulated and given to the President, and thereby dismissed the case for lack of jurisdiction, evidently wanting the process to play out more before entertaining a challenge. Justice Breyer, joined by Justices Sotomayor and Kagan, dissented, arguing that the case was ripe and the challengers should prevail on the merits.
A link to the decision is here: https://www.supremecourt.gov/opinions/20pdf/20-366_7647.pdf