She was first elected in 1998, and was re-elected every two years until her retirement in 2015. Prior to the 2002 legislative redistricting, she represented the old District 37B.[2]
She was an assistant majority leader during the 2001–02 session. She chaired the House Civil Law Committee during the 2003–04 session, and the House Transportation Finance Committee during the 2005–06 session.[2]
On November 20, 2003, Holberg and then State Senator Michele Bachmann proposed a constitutional amendment that would define marriage as one man and one woman.[3][4]
On May 21, 2011, she joined the House Republican majority in voting for 2012 Minnesota Amendment 1, a proposed constitutional amendment to define marriage as between a man and woman. The amendment was rejected by a majority of Minnesota voters.
Holberg announced on February 22, 2014, that she would not be seeking re-election.[5]
Dakota County Board of Commissioners
In 2014, Holberg campaigned for the open seat on the Dakota County Board of Commissioners vacated by retiring commissioner Paul Krause. Holberg received 62 percent of the vote in that election.[6] She won re-election to the seat in 2022.[7]