Eric Ching entered local politics by running as a challenger in the 2012 Walnut City Council election, where he secured the third seat by defeating incumbent John Saleeby by 32 votes after the counting of 622 additional vote-by-mail ballots reversed the initial results, leading to his installation on the council on April 25, 2012. During his first term, Ching fulfilled a campaign promise from 2012 by advocating for the removal of a
red-light camera in Walnut, which the city council approved in May 2014 as part of efforts to address community concerns. In July 2014, Ching was appointed as mayor pro tem of Walnut, a position that placed him in line for the mayoral rotation. During a contentious August 27, 2014, city council meeting, Ching objected alongside Mayor Nancy Tragarz to conducting a closed-session
performance evaluation of
City Attorney Michael B. Montgomery, amid discussions about terminating or renewing Montgomery's contract due to concerns over his performance, lack of
malpractice insurance, and
contract validity. At a subsequent tense three-hour meeting on September 9, 2014, Ching voted against renewing Montgomery's contract in multiple 2-2 deadlocked votes and proposed a motion to advertise the position and collect resumes, which also failed due to the split after
Councilwoman Mary Su's early departure for a family emergency. In October 2014, Ching voted against retaining Montgomery in a 3-2 council decision that approved the contract with added stipulations. Ching sought re-election in the April 12, 2016, Walnut City Council election amid heightened stakes due to issues like opposition to
Mount San Antonio College's proposed
parking garage and
solar farm,
public safety concerns from a 40 percent
burglary spike, and internal council divisions over leadership and the
city attorney position, which led to hiring a new attorney in March 2016. In the 2016 campaign, Ching received $30,764 in contributions as of February 27, 2016, and pushed for Measure A to impose
term limits on council members, allowing two four-year terms followed by a two-year break before a possible third term, while expressing concerns about Mount San Antonio College's projects increasing traffic and congestion in Walnut. The 2016 Walnut City Council race became combative and featured forums addressing traffic,
crime, and the college dispute. Ching won re-election in the 2016 Walnut City Council vote with 1,896 votes, placing second behind
incumbent Nancy Tragarz, and attributed his success to community recognition of his contributions while committing to work on a new city general plan and careful development planning for a lot near the Walnut
Sheriff's Station. Following the 2016 election, Ching attended the swearing-in ceremony on April 27, 2016, where 23-year-old Andrew Rodriguez was installed as the youngest council member in Walnut's history amid applause from a packed chamber, marking the addition of a new member after Tony Cartagena's departure after 16 years. In March 2017, as mayor of Walnut, Ching participated in a press event outside
West Covina City Hall alongside West Covina Mayor Pro Tem Mike Spence, West Covina
Police Chief Dave Faulkner, and
state Senator Joel Anderson to oppose California's
SB 54 sanctuary state bill, arguing that it would hinder
deportation of violent
felons in the country illegally by limiting local law enforcement's cooperation with federal
immigration authorities. During the same event, Ching specifically commented on the case of Haissam Massalkhy, a West Covina resident sentenced for
vehicular manslaughter in the death of Walnut
jogger Chi "Jason" Shao, stating that Massalkhy intentionally committed the crime to stay in the
United States and that the bill would shield such individuals from deportation. In 2020, Ching served another term as mayor pro tem of Walnut, continuing his involvement in local governance. In January 2023, following a mass shooting at a
Monterey Park dance studio that killed 10 people and injured 10 others during
Lunar New Year celebrations, Ching visited a local
senior center to offer help, expressing shock that such violence occurred in the quiet community where he felt safe even at midnight and noting he had never seen a
gun there before. == Congressional campaigns ==