Harless was appointed to the Texas Motor Vehicle Board overseeing the Texas Department of Motor Vehicles by Governor George W. Bush and later re-appointed by Governor Rick Perry, serving from 1998 to 2005.
[1] She was elected to the Texas House of Representatives in 2006 for the 126th district as a member of the Republican Party.
She was sworn in on January 8, 2007 succeeding Republican Peggy Hamric and was subsequently re-elected four times.
[3] In 2019, Sam Harless was elected to the Texas House of Representatives for her former district.
[10] She co-owns Fred Fincher Motors, a car dealership group founded by her parents in 1959, with her husband and previously served as CFO.