CNN– The Supreme Court said Monday that it will not take up a longshot challenge to Donald Trump’s eligibility to run for president because of his alleged role in the January 6, 2021, attack on the US Capitol.

The case was brought by John Anthony Castro, a little-known candidate for the Republican presidential nomination, who sued Trump earlier this year in an effort to disqualify him from running for president and holding the office “given his alleged provision of aid or comfort to the convicted criminals and insurrectionist that violently attacked our United States Capitol on January 6, 2021.”

The case was denied without any comment or recorded vote.

Castro’s case against Trump leans on a post-Civil War provision of the 14th Amendment that says any American official who takes an oath to uphold the US Constitution is disqualified from holding future office if they “engaged in insurrection or rebellion” or have “given aid or comfort” to insurrectionists.

This case is separate from the other 14th Amendment challenges against Trump in Minnesota and Colorado, which are scheduled for trials later this year.

The Constitution doesn’t spell out how to enforce this ban, and it has been applied only twice since the late 1800s, when it was used extensively against former Confederates.

“The framers of Section 3 of the 14th Amendment specifically designed it to remove overwhelming popular pro-insurrectionists from the ballot. As such, Castro is not simply within the ‘zone’ of interests; Castro is the precise type of person that the framers of Section 3 of the 14th Amendment specifically sought to politically protect while Trump is the precise type of person they sought to disqualify,” Castro told the justices in court papers.

A lower court had thrown out Castro’s case, ruling that he lacked the legal right – or standing – to bring the challenge, and his petition to the high court had asked the justices to decide whether he did have standing in the matter.

“A primary candidate has judicial standing to bring a claim challenging the eligibility of a fellow primary candidate for competitive injury in the form of a diminution of votes and/or fundraising if the primary candidate believes that the fellow primary candidate is ineligible to hold public office and to prevent actions irreconcilable with the U.S. Constitution,” Castro told the justices in court papers.

Castro isn’t a serious contender for the 2024 GOP nomination. He hasn’t met the requirements to participate in any of the GOP debates, and said in court papers that his campaign activities have largely centered around building a website and various photo-ops.

At least two other similar challenges to Trump’s eligibility have been brought in recent weeks by groups seeking to keep the former president from returning to the Oval Office. Those cases – in Minnesota and Colorado – are far more serious legal endeavors than Castro’s challenge, and they have the backing of a wide array of legal experts and constitutional scholars, though they still face long odds to prevail.

Trump denies wrongdoing and has vowed to fight to remain on the presidential ballot.

CNN’s Marshall Cohen contributed to this report.