[3] While at the firm, Park represented the state of Kansas in its efforts to cut Medicaid funding for Planned Parenthood.

[11][12][13] In 2016, Park represented the Kansas Department of Health and Environment in its effort to cut off Medicaid funding to Planned Parenthood.

[14] In 2017, Park led efforts to challenge an EPA rule under the Clean Water Act that sought to expand the statute's protection of wetlands.

[15] In 2018, Park worked on behalf of Project on Fair Representation to defend the Trump Administration's efforts to insert a citizenship question into the 2020 U.S.

[16] Park is an adjunct professor at the Antonin Scalia Law School, where he teaches the Supreme Court Clinic.

President Trump nominated Park to the seat vacated by Judge Gerard E. Lynch, who took senior status on September 5, 2016.

[21] Park was on a list the Trump White House sent to Schumer and Gillibrand in July that included three other names for the US Court of Appeals for the Second Circuit, where there were two vacancies: The other names were US District Judge Richard Sullivan; Matthew McGill, a partner at the law firm Gibson, Dunn & Crutcher in Washington and Nicholas Quinn Rosenkranz, a professor at Georgetown University Law Center.