US President Trump launched a fierce attack on the US Supreme Court on Tuesday, saying its ruling to block a controveRSIal new US Postal Service (USPS) mail-in ballot rule from taking effect for the upcoming midterm elections was "a big loss for the Republican Party".

Trump wrote on Truth Social that the Republican Party "just got another bad decision from the US Supreme Court". He accused the court of issuing the ruling after a long delay, then partly blamed insufficient time for the failure to implement solutions in a timely manner. He also claimed that America’s "completely corrupt and out-of-control mail-in voting 'disaster'" had made "cheating" eASIer.

This ruling is particularly critical for Trump’s Republican Party. The Republicans are currently trying to hold their slim majority in both chambers of Congress in the November election, and changes to mail-in voting rules may affect election organization and voting procedures.

Supreme Court temporarily blocks the new rule

On Monday, the US Supreme Court upheld an injunction issued by a federal district court judge in Boston, preventing the USPS new rule from applying to ballots sent out in the November election. The decision means the rule cannot be enforced in this midterm election for now.

Trump continued posting one day after the ruling was released, stating that this was not only a loss for the Republican Party but also "a loss for America itself". He again targeted what he called "radical left-wing Democrats", claiming it would make it eASIer for them to "cheat" with mail-in ballots.

Trump names and criticizes conservative justices

Trump also sharply criticized three Supreme Court justices he appointed, saying they appeared to side with the three liberal justices and Chief Justice John Roberts. He wrote: "These are not the people I interviewed and nominated to the US Supreme Court. They are just an empty shell of their former selves."

Trump also said the "shockingly bad rulings" handed down by the Supreme Court are costing America "trillions of dollars".

In this ruling, Justice Brett Kavanaugh, appointed by Trump, joined other justices in agreeing to temporarily block the rule from taking effect. In a separate opinion on Monday, Kavanaugh wrote that the postal rule "may well be found lawful ultimately", but he noted that applying the rule for the 2026 election would be "arbitrary and capricious", as state and local election officials would not have enough time to reasonably implement the rule before the election.

The other two justices appointed by Trump are Neil Gorsuch and Amy Coney Barrett.

A 7-2 majority emerges

Back in February this year, Gorsuch and Barrett joined conservative Chief Justice Roberts and three liberal justices in the majority in a ruling on Trump’s sweeping import tariffs. Trump said at the time their votes had embarrassed "themselves, their families and each other".

The majority Supreme Court ruling on Monday was unsigned, with only Kavanaugh writing a short concurring opinion. Two conservative justices, Samuel Alito and Clarence Thomas, publicly dissented from the decision, strongly suggesting the Supreme Court blocked the new USPS rule by a final vote of 7-2.

Trump later praised Alito and Thomas for their dissent, calling them "legends".