Former Republican presidential hopeful Rick Santorum has become the latest high-profile name involved in the Tennessee GOP governor's race by endorsing U.S. Rep. Diane Black.

Black's campaign announced the support of the former U.S. senator from Pennsylvania on Tuesday. Santorum praised Black for socially conservative stances, including anti-abortion views. Four leading Republican candidates are competing ahead of the Aug. 2 primary election. Early voting has already begun.

Santorum's endorsement follows the involvement of another former GOP presidential hopeful, ex-Arkansas Gov. Mike Huckabee, who has endorsed former state economic development commissioner Randy Boyd. Huckabee appears in some Boyd TV ads.

The campaigns have released laundry lists of endorsements. Businessman Bill Lee's latest noteworthy backer is former Congressman Zach Wamp. House Speaker Beth Harwell has touted the Tennessee Education Association's support.