The U.S. Supreme Court is jumping headfirst into turbulent waters with issues that have become politically divisive.

The 18th-century wartime authority to speed deportations known as the Alien Enemies Act is back in the high court’s hands.

Less than two weeks after the Supreme Court allowed President Donald Trump to employ the controversial authority, the issue was literally rocketed back to the justices in a short fuse appeal.

The consequences are enormous. So what’s really at issue here?