Republicans have reserved $1.75 million for television ads to help Carly Fiorina in the final week of the California Senate race.
The buy signals GOP optimism about unseating three-term Democratic Sen. Barbara Boxer in November.
Amber Marchand, a spokeswoman for the National Republican Senatorial Committee, confirmed the decision to invest in the bid of former Hewlett-Packard CEO Fiorina. Previously, the committee had declined to say where it would be putting its money going into the Nov. 2 election.
The committee has been reluctant in the past to spend money in California races because Democrats have a huge edge in voter registration and races are so expensive.