Here's what you need to know about Trump's assertion of executive privilege and what's ahead in the debate over the citizenship question.
The five conservatives on the court seemed ready to rule against three lower courts, a collection of researchers and experts, and five former leaders of the Census Bureau.
Uncertainty over the government's future operations and the addition of a citizenship question have left cities bracing for chaos during the upcoming census.
Six lawsuits challenging the legality of the citizenship question, filed by various groups including the states of New York and California, are now pending in federal courts.
The 2020 census will be the first in the nation's history to be conducted electronically, which will also mean more potential for outside interference.
Wilbur Ross ignored many Census Bureau officials' warnings and will include a question about citizenship status in the census for the first time since 1950.
California's attorney general has already challenged the Trump administration's decision to include the question in federal court.
A group of Senate Democrats is requesting an investigation into Wendy Teramoto's business ties to the Russian president's billionaire associates.