McCune began his career as a provider of Copper River salmon products. He later served on the board of the Prince William Sound Aquaculture Corporation. McCune served as a member of the Washington House of Representatives in 1998. In 2004, he was again elected to the House, serving until 2013.[2]
He served as a member of the Pierce County Council, representing the 3rd district from 2013 to 2021.[3]
After incumbent Republican Randi Becker announced her retirement from the Washington State Senate, effective after the end of the 2020 legislative session, McCune announced his candidacy to succeed her.[4][5] McCune placed first in the August 2020 Republican primary and faced Marilyn Rasmussen in the November general election.[6]