Kersey unsuccessfully ran for the Solana BeachCity Council in 2004. Kersey's candidacy was supported by the Beach and Bluff Conservancy, a local homeowners group that supported building seawalls to protect their property. Their political action committee spent $18,800 in his behalf during his unsuccessful effort to win a seat on the Solana Beach City Council. During the race for Solana Beach City Council, Kersey had to retract claims that several people had endorsed him after those individuals stated that they, in fact, had not given him their endorsement. This factored into the decision of the Solana Beach Firefighters Association to pull its endorsement of Kersey, as well. In 2008 he was the president of San Diego Young Republicans and was elected to the San Diego County Republican Central Committee.
San Diego City Council
In 2011 Kersey announced he would run for San Diego City Council in the 2012 election. He was part of a coordinated three-person slate supported by the localRepublican Party in an attempt to gain a Republican majority on the nine-member board. He ran unopposed for the District 5 seat being vacated by retiring councilmember Carl DeMaio. District 5 includes the neighborhoods of Black Mountain Ranch, Carmel Mountain Ranch, Rancho Bernardo, Rancho Encantada, Rancho Peñasquitos, Sabre Springs, San Pasqual Valley, Scripps Ranch, and Torrey Highlands. He was elected in the June primary by receiving more than 50% of the vote. Kersey took office December 3, 2012. He chairs the Infrastructure Committee, is vice chair of the Economic Development and Intergovernmental Relations Committee, and is a member of the Budget and Finance Committee and Charter Reform Committee. Kersey is also the City's representative to the CaliforniaLeague of Cities. Kersey has been called San Diego's "open data and infrastructure guy." Kersey was elected to a second term in June 2016. In December 2016, Kersey was appointed Council President Pro Tem. He served in this position until December 2017, when he was succeeded by Barbara Bry. In April 2019, Kersey declared that he was leaving the Republican Party to become an independent, stating that he would work toward bipartisan solutions to the City's issues during the remaining two years of his term.
Infrastructure
As chair of the Infrastructure Committee, Kersey spearheaded a plan to address the City of San Diego's approximately $2 billion backlog of infrastructure projects. The plan called for assessments of city infrastructure, streamlining of processes, gathering of neighborhood input and the creation of a long-term infrastructure investment plan. With Kersey's leadership, the city completed its first-ever comprehensive sidewalk assessment as well as its first multi-year capital plan, which identified $1.7 billion in unfunded infrastructure projects over the next five years. Kersey also sponsored an ordinance to create a neighborhood input policy which was approved in July 2013. The policy formalized community input as part of the infrastructure prioritization process.
Open data
Kersey has pushed an open data initiative to "increase accountability and spur innovation" by putting the City's data online for the public. Kersey co-authored a draft open data policy and voted to create an ad-hoc committee to review and develop a formal policy to be adopted by the City of San Diego. The final policy was approved by the Council on December 16, 2014. Kersey also proposed creating a centralized communications point for San Diego City services, known as a 3-1-1 system. Kersey said 3-1-1 would be a number people could call if they have potholes on their street, broken traffic lights or spot water leaks in the city.
Other actions
In September 2013, he sponsored an ordinance to streamline the permit process, meant to help reduce costs and the time associated with completing city construction projects.
In December 2017, Kersey formally announced his candidacy for the California State Senate to succeed fellow Republican Joel Anderson, who is barred by term limits from seeking another term. In March 2018, he announced that he was ending his campaign due to family health issues.
