The U.S. Senate passed a bill on Tuesday that would protect federal recognition of same-sex marriage, a measure taken up in response to worries the Supreme Court could overturn a 2015 decision that legalised it nationwide.

The narrowly tailored bill, which would require the federal government to recognise a marriage if it was legal in the state in which it was performed, is meant to be a backstop if the Supreme Court acted against same-sex marriage. It would not bar states from blocking same-sex or interracial marriages if the Supreme Court allowed them to do so.