President Donald Trump faces an uphill fight convincing the Supreme Court it should grant his emergency request to reinstate his travel ban on people entering the United States from six predominantly Muslim countries.

His legal team on Thursday night asked the nine justices to allow his controversial March 6 executive order to take effect immediately despite being blocked by lower courts. The Supreme Court rarely grants emergency requests.

At issue is a ban Trump has said is necessary to protect Americans from terrorist attacks. Critics say his reasoning is flawed and assail the ban as discriminatory. Trump's proposed ban was a centerpiece of his 2016 presidential campaign.