The United States Supreme Court is to announce at least a single verdict on Monday, the day before Colorado's presidential primary voting, in which a lower court removed Republican frontrunner Donald Trump from the ballot for his role in the 2021 Capitol attack.

In an uncommon Sunday schedule change, the court did not indicate the decision it would issue. However, on February 8, the justices heard arguments in Trump's appeal of the Colorado case and are expected to make their own conclusion.

Colorado is one of 15 states and an American territory that conducts primary elections on "Super Tuesday." 

The Republican Party of Colorado has requested the Supreme Court, whose 6-3 conservative majority includes three Trump-appointed justices, to decide on ballot eligibility by Tuesday.

During arguments in the case, Supreme Court justices expressed sympathy for Trump's appeal of a Dec. 19 verdict by Colorado's highest court.

The ruling, which only applies to the Colorado primary ballot, is the first of several legal actions across the country, aimed at invoking the US Constitution's 14th Amendment, which bars from office anyone formerly sworn to protect the country who later engages in insurrection.

A ruling in Illinois last week also declared that Trump cannot run for the 2024 presidential election in the state. The decision, arising from a lawsuit by Illinois voters, is grounded in a provision of the state's Election Code preventing candidates involved in "insurrection" or rebellion against the United States from seeking office.

Last Wednesday, the Supreme Court agreed to hear Trump's claim of immunity from prosecution for attempting to overturn his 2020 election defeat.

Cook County circuit judge Tracie Porter concurred with the plaintiffs, determining that Trump's conduct on January 6, 2021, constituted "insurrection". As a result, she ruled that he was ineligible to hold office according to the Illinois Constitution.

Trump beats Haley, wins Missouri, Michigan Republican caucuses

Trump on Saturday swept to victory in the Republican caucuses in Michigan, a contested state for the party that some Republicans fear could hurt his campaign in the key battleground state as he gears up for the election in November.

The former US President also won the latest Republican presidential nomination vote on Saturday, defeating competitor Nikki Haley in Missouri.

Results from a compilation of a dozen polls by RealClearPolitics revealed on Wednesday that the approval rating of former US President Donald Trump has skyrocketed to its highest level since 2022. 

The Associated Press declared Trump the winner of the Missouri race when just a small percentage of ballots were counted.

Trump has won each nominating contest by a large majority, putting him on course to secure the Republican presidential nomination by mid-March.