In 2000, Bennett was the Libertarian nominee for the office of Lieutenant Governor. She campaigned on the platform of abolishing the position of Lieutenant Governor and earned 7% of the vote. This qualified the Libertarian Party for ballot access in the next election.
In 2004 Bennett campaigned for the office of Governor. Her campaign heavily emphasized gay rights, specifically the legalization of same-sex marriage in the state of Washington. Many Washingtonians, including the chair of the Republican Party and the Republican and Democratic gubernatorial campaigns, attribute the race's being so close to her candidacy, as it is believed to have attracted many gay and liberal voters who might otherwise have voted Democratic, and fiscal conservatives to whom the Libertarian Party appeals. She received over 63,000 votes (2.25%), whereas the Democrat (Christine Gregoire) beat the Republican (Dino Rossi) in the final recount by a mere 129 votes (0.0045%).