The Supreme Court has cleared the way for US President Donald Trump to move ahead with his executive order restricting mail-in voting, though it remains unclear how much his administration can implement before the fast-approaching midterm elections.
The decision on Monday appears to leave room for additional court challenges that could further slow Trump's order.
And with some states beginning to send mail ballots to voters in just a few weeks, time is running short to impose major changes.
Mail balloting has long been a favourite target for the Trump administration, which said that it breeds fraud.
The case could be one of multiple voting-related challenges before the justices. The Justice Department had filed an emergency appeal asking the high court to allow work on implementing the changes before the midterms.
Trump's executive order, signed in March, calls on his administration to create lists of eligible voters and orders the US Postal Service to deliver mail ballots only to people on those lists.
'Rushed effort'
In June, Judge Indira Talwani ruled that the president lacked the authority to order changes in how states administer federal elections, noting that under the US Constitution, states have the role of determining voter-eligibility requirements.
The judge also noted that federal agencies lack the ability to compile accurate lists of citizens for each state.
The states contend that their claims are not hypothetical and that the administration's "rushed effort to change the rules of mail voting on the eve of the November midterms risks disenfranchising a substantial number of voters."
The judge rejected the administration's arguments, finding that the suit was not filed too soon and that the states had legal standing because they would face election administration disruption, compliance costs and a credible threat of criminal prosecution.
