The Supreme Court rejected President Donald Trump’s bid to impose new requirements on mail ballots on Monday, Sept. 14, blocking the rules from being enforced during the 2026 midterm elections.

With mail voting already underway in some states, the decision means Colorado will be allowed to mail ballots to all registered voters under state law.

“This Supreme Court decision is good news for our democracy,” said Colorado Gov. Jared Polis in a statement. “Colorado has gold-standard elections, and this decision allows Colorado’s secure elections to proceed without confusion, chaos and bureaucratic blockades meant to make it harder for Coloradans to vote. … The Trump Administration’s efforts would have made it harder for election officials to administer free and fair elections.”

Trump signed the executive order in March, directing the U.S. Department of Homeland Security to compile a list of U.S. citizens based on federal databases and mandating that the U.S. Postal Service only send mail ballots to voters on that list. 

The order would have also changed how mail-in ballots can be sent, including adding requirements that states use unique identifiers — like barcodes — on ballot envelopes to “reduce the risk of fraud” and protect election integrity.

In an opinion published Monday night, six Supreme Court justices wrote that the administration’s push to implement restrictions that would have limited mail-in ballots ahead of the midterm elections is likely to lose in court. Two justices — Samuel Alito and Clarence Thomas — dissented.

Another justice, Brett Kavanaugh, said he supported blocking the restrictions from going into effect for the midterms, but might rule in favor of the Trump administration if the issue comes back before the court at a later time.

The Supreme Court decision comes less than three weeks after Colorado joined two dozen other states in a lawsuit against the U.S. Postal Service to block the new set of rules for mail-in voting, which election officials said would be too cumbersome to implement in time for the 2026 midterm elections.

“I respect the Court’s decision,” said Rep. Jeff Hurd, a Republican representing Colorado’s 3rd Congressional District, in a statement to The Aspen Times. “Elections should be secure, voters should have confidence in the results, and the rules governing an election should be clear well before voting begins. Colorado has administered elections by mail for years, and changing those procedures just weeks before an election would create unnecessary uncertainty for voters and county clerks.”

Colorado has sent mail ballots to every active registered voter in the state since 2013, with the option to vote in person at polling centers. Today, the vast majority of Coloradans choose to return their ballot by mail or at a drop-off box.

Trump has repeatedly claimed that voting by mail has led to mass fraud, despite the president casting a mail ballot as recently as August, according to reporting by Politico. A 2025 analysis by the Brookings Institution found that cases of fraud involving mail-in voting are very rare, translating to four instances of fraud for every 10 million mailed votes.

“House Democrats took our fight against Donald Trump’s disastrous attempt to impose unworkable restrictions on mail-in voting to the highest court in the land — and won,” said Rep. Joe Neguse, a Democratic representing Colorado’s 2nd Congressional District, in a statement. “We’ll never stop fighting to vindicate our Constitution and put a stop to this administration’s efforts to disenfranchise American citizens. No party, and certainly no president, is above the rule of law.”

In April, Colorado Attorney General Phil Weiser responded to Trump’s executive order by joining 22 states in a lawsuit to prevent the mail voting changes, which resulted in a federal judge blocking the order from taking effect in those states in July.

The Supreme Court’s conservative majority later lifted the lower court’s block on Trump’s order on Aug. 24, after an appeal from the Trump administration. Weiser joined two dozen other states in a new lawsuit against the U.S. Postal Service just two days later, arguing that the order’s provisions violated the authority of states and Congress to pass election laws. Their lawsuit also claimed that the Postal Service’s rules went against federal voting rights laws and violated the Privacy Act.

“Congress and the states each have constitutional responsibilities when it comes to federal elections, and any changes should be made through the appropriate legal process and with enough time to implement them responsibly,” Hurd said in his statement.

The Supreme Court’s Sept. 14 decision comes just weeks before Colorado county clerks start mailing ballots to registered voters beginning Oct. 2. Coloradans can return ballots at drop boxes across the state starting Oct. 12, and early voting centers will be open statewide beginning Oct. 19.

Prior to the Supreme Court’s latest decision, local and state election officials had expressed concerns that the rules posed by Trump’s order would be burdensome to implement so soon before the midterm elections. Voting rights groups feared the sudden changes would disenfranchise voters.

“Today, the Supreme Court rightfully rejected President Trump’s latest attempt to infringe on Americans’ right to vote and avoid accountability for his disastrous record,” said Democratic U.S. Sen. John Hickenlooper in a statement. “Colorado has proven that mail-in voting is safe, secure, and cost-effective. We’ll keep standing up to President Trump’s attacks on democracy and protecting every American’s fundamental right to choose their representatives.”