Supreme Court hearing gets awkward as conservative Alito runs roughshod over chief justice Roberts

President Trump is pressing the U.S. Supreme Court to allow him to exclude undocumented immigrants from the census count -- a move that goes against more than 200 years of practice where non-citizen residents, even those in the U.S. illegally, were among those counted.

While questioning New York Solicitor General Barbara Underwood, conservative Justice Samuel Alito said that the prospect of submitting two documents, one detailing census numbers of every person inside the U.S. and another detailing numbers that exclude undocumented immigrants inside the U.S. "seems like a totally meaningless formality."

"It's not a meaningless formality in the sense that this is the moment in the process when judicial intervention can operate," Underwood replied, adding that the court can tell President Trump what is "lawful to use in his report to Congress."

Later in the exchange, Chief Justice John Roberts signaled to Alito that his time was up and attempted to hand over the floor to Justice Sonia Sotomayor, but Alito ignored Roberts and insisted on moving on to his second point.

Listen to the exchange in the video below: