The ruling left unsettled the question of whether children born to immigrants without full legal status in the United States are entitled to automatic citizenship. So what happens now?

President Donald Trump's attempt to halt birthright citizenship for some babies born to immigrants will not take effect in Massachusetts, Attorney General Andrea Campbell said Friday, but a U.S. Supreme Court ruling complicates the outlook in red states.

Effective immediately, the Trump administration can begin planning for how it would implement an end to birthright citizenship.