DES MOINES, Iowa - It has been a busy day for the Rick Santorum campaign, which reeled in two endorsements for the former Pennsylvania senator that he can tout on the campaign trail in the last two weeks before the Iowa caucuses.

Sioux City talk-show host Sam Clovis is backing Santorum, the first time he has endorsed a candidate in the caucuses. He has a popular conservative radio show on KSCJ, an ABC News affiliate.

Clovis said in a statement that his listeners were "always asking me who I will be supporting in the upcoming caucuses" and "it's time to take a stand and let people know."

He said he's supporting Santorum because he is an "ideal candidate" who believes in "a constitutionally limited government, fiscal responsibility, strong national defense and unflagging devotion to life and traditional marriage."

Clovis had Rep. Michele Bachmann on his show Friday. The two spoke about Rep Ron Paul's comments on Iran at Thursday night's Fox News debate in Sioux City and Bachmann called them "disqualifying."

Santorum said in a release that Clovis' support in the GOP presidential race is a "terrific boon to our campaign and an honor to receive. The momentum continues building for us, and I am thrilled to have Sam as part of our team as we put our plan to win the Iowa caucuses into action."

The campaign also received the backing of a more unexpected endorser, bestselling thriller author Brad Thor. He is a successful writer who also does some conservative commentating. Thor said in a statement that Santorum is the "one presidential candidate who understands and can swiftly address the threats facing our nation."

"Rick knows that the world would be forever changed by Iran getting a nuclear weapon, and he has sworn to keep this from happening. I am excited to add my endorsement to the growing list of prominent supporters who understand that Rick Santorum is the right man, at the right time to lead our nation," Thor said.

Santorum has also received the backing recently of the state's secretary of state, Matt Schultz, and several high-profile Iowa pastors. He has barnstormed the state for months running the most traditional Iowa campaign, but has yet to shoot up in the polls or enjoy the kind of boomlet the other candidates have experienced.

Such high-profile endorsements are more fodder for both Santorum and his campaign to make the claim that the momentum continues to build in the state so he can sell electability to still-undecided caucus goers.