Thune backs Fiorina in California primary (updated)

California Senate candidate Carly Fiorina (R) continues to rack up endorsements from establishment Republicans.

On Friday she rolled out the endorsement of Sen. John Thune (R-S.D.). The first-term senator, who gained fame when he defeated then-Senate Majority Leader Tom Daschle (D) in 2004, is a darling of the conservative movement.

"I am proud to endorse Carly Fiorina today because she is a principled leader who will add an important and much-needed real-world perspective to the dialogue in the U.S. Senate, especially in light of our nation’s economic struggles," Thune said in a statement.

Fiorina is also backed by Senate Minority Leader Mitch McConnell (Ky.) and several other high-profile conservatives, including Sarah Palin. 

The latest Capitol Weekly/Probolsky Research tracking poll shows Fiorina leading former Rep. Tom Campbell (R-Calif.) 36.5 percent to 22 ahead of Tuesday’s primary.

(An earlier version of this post stated incorrectly that Dick Cheney had endorsed Fiorina. The former vice president hasn't endorsed in the GOP Senate primary. He's endorsed former eBay CEO Meg Whitman in the GOP gubernatorial primary.)