Prolific Challenger of Trump’s Ballot Eligibility Faces Federal Tax Charges

A long-shot Republican presidential candidate who has repeatedly, and so far unsuccessfully, tried to have Donald J. Trump thrown off the primary ballot was arrested this week on federal charges of preparing false tax returns for clients.

The candidate, John Anthony Castro, faces 33 felony counts of aiding and assisting in the preparation and presentation of a false and fraudulent return. Each count carries a sentence of up to three years in prison if he is convicted.

Court records show that prosecutors filed an indictment of Mr. Castro under seal on Jan. 3. That same day, Mr. Castro represented himself in a New Hampshire courtroom, appearing without a lawyer to contest Mr. Trump’s eligibility.

The records in the criminal case against Mr. Castro, which are now public, show that he was arrested by federal agents on Tuesday and was released after making an initial appearance in federal court in Fort Worth.

Mr. Castro graduated from law school but has never been licensed to practice law in any state. His bare-bones presidential campaign had raised $678 as of September, and he has not emerged as a serious challenger to the leading Republican candidates.

Even so, Mr. Castro has made headlines for a fire hose of litigation in at least 27 states, asserting that Mr. Trump is barred from the presidency by Section 3 of the 14th Amendment, which excludes from office any federal or state official who “engaged in insurrection or rebellion.”

Several of Mr. Castro’s lawsuits remain pending, either in trial courts or on appeal, but to date, none of them have gained significant traction. Some judges have questioned whether he had standing to sue on the issue, and have expressed doubts that he was a serious candidate for the presidency. Earlier this week, a federal judge in Nevada dismissed Mr. Castro’s lawsuit in that state, finding that by running for president, he was “creating his own injury in order to manufacture standing.”

The criminal charges against Mr. Castro, who has prepared income tax returns for clients of his business, accuse him of repeatedly promising to help those clients get a higher tax refund than other preparers could, and of claiming false deductions on their returns without the clients’ knowledge. The indictment claims he “devised and executed a scheme to defraud the United States by falsely creating and submitting false tax returns on behalf of unsuspecting taxpayers.”

In a phone interview on Wednesday, Mr. Castro claimed he was being persecuted and retaliated against by Trump appointees. He said the allegations in the indictment involved actions he took years ago and that he had previously taken responsibility for misinterpreting the tax code in those instances. He added that he thought the charges against him were an attempt to disrupt his lawsuits regarding Mr. Trump.

“They sat on it for three years to see if I would stop being a problem, politically, and go away, and I didn’t,” said Mr. Castro.

He said the charges might affect his plans to file more lawsuits around the country on the ballot eligibility issue, because he now needs the court’s permission to leave Texas.

A spokeswoman for the federal prosecutor’s office in the Northern District of Texas, where Mr. Castro lives and where the indictment was filed, declined to comment on the case. The U.S. attorney in that district, Leigha Simonton, was nominated by President Biden.

Court records show that Mr. Castro plans to hire a lawyer to defend him, and that he is due back in court next week for arraignment.

Though Mr. Castro’s attempts to disqualify Mr. Trump have so far been unsuccessful, other challenges have emerged as significant threats to the former president’s candidacy. The Colorado Supreme Court and Maine’s secretary of state, a Democrat, have each found Mr. Trump ineligible to appear on their states’ primary ballots because of the 14th Amendment. Both decisions are being appealed; the Colorado case has reached the U.S. Supreme Court, which is scheduled to hear oral arguments next month.

Formal challenges to Mr. Trump’s presidential candidacy have been filed in at least 34 states, according to a New York Times review of court records and other documents. In at least 19 of the states, the challenges remain unresolved. The Trump campaign has repeatedly criticized the attempts to disqualify him as partisan, unconstitutional and antidemocratic.