[14] He interacted with rioters, many carrying Make America Great Again and Confederate flags, and members of the Oath Keepers such as Kelly Meggs.

In his testimony, Dunn said that rioters had used racial slurs against him during the attack[19][20] and that he has attended psychotherapy and engaged in peer support to help him process the trauma he experienced.

[23] Dunn testified in the 2022 trial of the Oath Keepers for seditious conspiracy for their actions relating to the Capitol attack.

[27] He officially entered the race on January 5, 2024, running in a crowded Democratic primary field that includes five state legislators—Mark S. Chang, Sarah Elfreth, Terri Hill, Clarence Lam, and Mike Rogers.

[29][30] As a result of his strong fundraising ability and online presence,[31] Dunn was seen as a frontrunner in the race alongside Elfreth and Lam.

[34] During the Democratic primary, Dunn campaigned on a platform involving democracy-related issues, abortion, infrastructure, health care laws, and gun reform.

[35][36] He received endorsements from various Democratic celebrities, including U.S. representatives Nancy Pelosi, Jim Clyburn, Adam Schiff, and Jasmine Crockett,[37][38][39] but none from elected officials within the district.

[34] Dunn pledged not to accept campaign contributions from corporate political action committees (PACs) and criticized AIPAC for getting involved in the primary by running ads for Elfreth.

Dunn also voiced support for a bill to provide $74 billion in funding to Ukraine and Israel and humanitarian aid to the Gaza Strip.

[44] Dunn was defeated in the Democratic primary election by state senator Sarah Elfreth on May 14, 2024, placing second with 25.0 percent of the vote.

[46] Following his defeat, Dunn started his own political action committee, Democracy Defenders PAC, to support candidates running against pro-Trump Republicans.

According to the internal memo obtained by Punchbowl News, Dunn's wife allegedly waved a kitchen knife in Dunn's direction, prompting him to retrieve his service weapon and rifle, which were stored in a department-issued lockbox with a broken locking mechanism, a violation of U.S. Capitol Police policy that led to a four-day suspension without pay.