In 2010, Davis was appointed by Gov. Bob McDonnell (R) to serve as director of the Virginia Liaison Office in Washington, D.C.. She resigned the post before declaring her bid for governor.

In 2003, Davis was elected the only female Republican member of the Virginia State Senate. She served a single term, from 2003 to 2007, having run unsuccessfully for re-election in 2007. While serving in the state Senate, Davis was a member of the following committees:

• Privileges and Elections Committee
• General Laws and Technology Committee
• Transportation Committee
• Social Services and Rehabilitation Committee
• Rules Committee

Subcommittee on Studies, Chair

Davis was first was elected to the Virginia House of Delegates in 1997 by voters from the legislative district covering portion the Town of Vienna, Fairfax County and the City of Fairfax. She was re-elected twice, and in her third term, her Republican colleagues voted her Majority Whip.