[8] In October 2016, Oosterhoff was nominated as the Progressive Conservative candidate in Niagara West—Glanbrook to replace Tim Hudak, who resigned his seat that September.

[6][10][11] Social conservatives such as Charles McVety accused Brown of muzzling Oosterhoff during the campaign because of the candidate's opposition to the new sexual education curriculum.

[19] Oosterhoff was widely criticized on April 20, 2018, for his televised rendition of African-American spiritual 'Nobody Knows the Trouble I've Seen' given his socially conservative views and trouble-free middle class upbringing.

[20] On October 31, 2018, Halloween, Oosterhoff celebrated the passing of the Cap and Trade Cancellation Act with a rendition of "Monster Mash" at Queen's Park.

[21] In May 2019, Oosterhoff participated in an anti-abortion rally at Queen's Park hosted by March for Life, where he made a stage appearance.

"[22] In October 2020, amid the COVID-19 pandemic in Ontario, Oosterhoff took group photos with about forty people in a banquet hall, none of whom were wearing masks or social distancing, which was contrary to provincial public health measures.