A Republican, Ertel previously served as Supervisor of Elections for Seminole County, Florida, a position which he was first appointed to by Governor Jeb Bush in February 2005.

When longtime Seminole County Supervisor of Elections Sandy Goard resigned from her office in 2003, Dennis Joyner was appointed as her replacement.

He was endorsed by the Orlando Sentinel, which praised him for the fact that he "has run elections well and has taken creative approaches to voter registration and streamlining of office operations.

"[6] In 2013, Ertel received the International Electoral Ergonomy Award from the International Centre for Parliamentary Studies for his work as the Seminole County Supervisor of Elections; specifically, they praised him for the fact that the Voter Trust Plan he implemented increased voter confidence, increased turnout, and was "exemplary for election management bodies worldwide.

[8][9] However, when photos of Ertel dressed as a "Hurricane Katrina victim" in blackface at a Halloween party in 2005 were leaked by the Tallahassee Democrat on the morning of January 24, 2019, he resigned on the same day.