The president issued his first travel ban just a week after taking office in January 2017, prompting widespread chaos and protests at airports and in cities across the US. Although the administration sought to modify the policy to pass legal muster, different versions of the travel ban have since been rejected as unconstitutional by federal judges in Hawaii, California, Maryland and Virginia.
The appeals process ultimately forced the conservative-leaning supreme court to determine the validity of the travel ban, which in its third version seeks to bar or limit entry to immigrants from five Muslim-majority countries – Iran, Libya, Somalia, Syria and Yemen. The policy also imposed travel restrictions on certain government officials from Venezuela and their families, as well as North Korea, which were not challenged in court.
https://www.theguardian.com/us-news/2018/jun/26/trump-supreme-court-upholds-travel-ban