Portland

From 2013 to 2015, he served as the Assistant City Manager for the City of South Portland, Maine. At the time of his hiring, Dan Boxer, an adjunct professor at the University of Maine School of Law, raised questions about a potential conflict of interest between Jennings's role as a partner in the Thompson's Point project, located in Portland, and his responsibilities as South Portland City Manager, which included attracting businesses that could potentially compete with his Thompson's Point project.^[9]

From 2015 to 2021, he served as the City Manager for the City of Portland, Maine.^[10] As Portland City Manager, was described by the Portland Press Herald newspaper as "public enemy No. 1 for progressives," as Jennings pushed for the closure of the India Street Health Clinic, ending general assistance for asylum-seekers, limiting access to the city's homeless shelters, against a $64 million municipal bond to renovate elementary schools, and against the city's passage of the nation's toughest pesticide ban mandating organic lawn management which when passed over his objections he underfunded.^{[11][12][13][14][15]} In 2015, Jennings blocked implementation of a plan that was approved unanimously by the City Council to redesign Franklin Street following a long community process. The plan was revived in 2023, two years after he resigned.^[16]

Jennings had long-running feud with elected Portland Mayor Ethan Strimling and faced sharp criticism from local Black Lives Matter activists, who in 2020 called for him to be fired.^[17][18] Elected members of the city council defended Jennings against the criticisms from Black Lives Matter.^[19] However, Portland voters in 2021 voted to create a charter commission to consider various changes to the city's form of government, including eliminating the office of city manager and replacing it with an elected, executive mayor.^[20]

Jennings resigned as city manager in 2021, before his contract expired, pointing to ongoing criticism from anti-racism activists as his reason for leaving.^[21]

Clearwater

On September 2, 2021, the Clearwater city council voted to hire Jennings as its next city manager.^[22] In December 2021, Jennings met with Church of Scientology leader David Miscavige, who has stirred controversy by purchasing extensive real estate in downtown, much of which sits vacant.^[23] In 2022, Jennings was accused of helping the Church of Scientology cancel a planned 81-unit affordable housing project in order that the church could open a museum to its founder on the site instead.^[24][25] On January 5, 2023, the Clearwater city council voted in the second of two required votes to terminate the contract of Jennings as City Manager with immediate effect, citing long term and growing concerns over Jennings lack of communication with them, focusing on late and incomplete delivery of information needed for important votes and being kept in the dark in matters involving the Imagine Clearwater project and discussions with Church of Scientology leader David Miscavige.^[26]