A 22-year-old who participated in the Jan. 6 riot at the U.S. Capitol lost his bid to unseat a Republican incumbent in the South Carolina House of Representatives.

The defeat of Elias Irizarry in the state primary on Tuesday is the latest in a number of losses that riot participants have suffered at the ballot box in recent months. Most recently, Derrick Evans, a former West Virginia lawmaker who pleaded guilty to a felony for his role in the attack, was defeated in a Republican primary in May for a congressional seat there.

Mr. Irizarry graduated last month from the Citadel, the esteemed public military college in Charleston, S.C. He was running in House District 43, a rural area in the northern part of the state. The incumbent, Randy Ligon, will not face a Democratic challenger in the general election, and will serve a fourth term in office.

Mr. Irizarry was sentenced to 14 days in jail after pleading guilty to a trespassing charge related to his participation in the 2021 riot. He was suspended from the Citadel for a semester but was later reinstated after a federal judge, Tanya S. Chutkan, wrote a letter to the school stating that Mr. Irizarry had demonstrated “remorse and a determination to make amends.”

Before his sentencing, Mr. Irizarry told Judge Chutkan that he was ashamed of his participation in the storming of the Capitol. But in the run-up to the election, his campaign website noted his prosecution for engaging in “nonviolent activities” at the Capitol as proof that he had “always stood for the conservative movement.”

That reference to Jan. 6 disappeared from the website last week after The New York Times discussed it with Mr. Irizarry’s federal public defender. In a text message, Mr. Irizarry said he had initially mentioned his involvement in the riot on his website “for the sake of transparency.”