In the months leading up to the race, the campaigns of both Mar and his primary opponent, Jessica Ho, were criticized for "mudslinging" tactics.

Mar is the author of a number of ordinances reforming San Francisco's electoral system and addressing money in politics, including 2019's Proposition F[10] addressing pay-to-play politics, corporate contributions, and dark-money donations, and Public Financing 2.0, which tripled the impact of San Francisco's public financing program for elections.

[14] Mar spearheaded multiple Board of Supervisors resolutions which denounced California State Senator Scott Weiner's SB 50 bill, which would have legalized higher density housing development in areas close to public transit.

[17] When asked to comment on legislation that would permit construction of fourplexes across the city, Mar said "a modest density increase to single-family zoning is certainly worth considering" in San Francisco but did not specify further.

[21] In January 2022, Mar defended the delay in approval for a $18.7 million grant to repurpose a hotel into a homeless shelter for upwards of 250 people.