The Supreme Court just upheld Trump's travel ban

Eric Thayer/Reuters

Police officers stand in front of the U.S. Supreme Court in Washington, DC, U.S., January 19, 2018.

• The Supreme Court on Tuesday upheld President Donald Trump's travel ban.
• The justices ruled that presidents have substantial power to regulate immigration.
• The plaintiffs had argued in their lawsuit that Trump's travel ban was discriminatory against Muslims.

The Supreme Court on Tuesday upheld President Donald Trump's controversial travel ban, in a 5-4 decision that split the justices along partisan lines.

The travel ban was Trump's third attempt at restricting travel from certain majority-Muslim countries after federal courts blocked the previous two.

The third ban imposed restrictions on travelers coming to the United States from Syria, Iran, Yemen, Somalia, Libya, North Korea, and Venezuela.

At issue in the case, Trump v. Hawaii, were two main questions: whether Trump has the authority under federal immigration law to implement such travel restrictions, and whether the travel ban violates the Constitution's establishment clause, which prohibits the government from favoring one religion over another.

Chief Justice John Roberts wrote the majority opinion, declaring that presidents have the authority to substantially regulate immigration.

The court's conservative-aligned justices voted to uphold the ban, with justices Anthony Kennedy, Samuel Alito, and Neil Gorsuch concurring with Roberts' opinion. The more liberal justices, including Stephen Breyer, Elena Kagan, Sonia Sotomayor, and Ruth Bader Ginsburg dissented.