In the wake of President Trumpadding Chad to his proposed travel ban back in September, the Supreme Court has voted to allow his administration to fully enforce it, AP reports.

The justices had two dissenting votes, and said that the policy "can take full effect even as legal challenges against it make their way through the courts." This action implies the high court could uphold the latest version of the ban that Trump announced.

The ban applies to six mostly Muslim countries and includes three African countries: Chad, Libya and Somalia. Syria and Yemen are the other countries under the ban.

Lower courts have said people from those countries with a claim of a "bona fide" relationship with someone from the U.S. could not be kept out of the country, like grandparents, cousins and other relatives. Justices Ruth Bader Ginsburg and Sonia Sotomayor would've left the lower court orders in place.

The 9th and 4th U.S. Circuit of Appeals will be holding arguments on the legality of the ban this week, and both courts are dealing with the issue on an accelerated basis, AP says.

Here are more reasons why this version of the ban has been harder to fight in court: