This is not the first time Rice has weighed in on a contested race between two Republican incumbents this cycle: She also endorsed Rep. Adam Kinzinger (R-Ill.) over fellow Rep. Don Manzullo (R-Ill.) earlier this year.

She had largely avoided the political realm since she rejoined the private sector in 2009 but has become increasingly involved this election cycle. She also held two fundraisers, one for Mitt Romney and one for female Republican candidates, in late June. Some think she may be a possible choice for Romney's running mate.

Quayle and Schweikert will face off on Aug. 28, one of the last primaries in the country. The winner will be all but guaranteed another term in Congress in the safely Republican seat.