Rick Santorum's sudden rise in the Iowa polls has the state's most vocal anti-gay marriage leader bragging about his endorsement, POLITICO.COM reported.

Bob Vander Plaats, who heads the Christian conservative group The Family Leader, gave his personal endorsement to Santorum last week.

Vander Plaats is best known for leading last year's successful campaign to oust three of the seven Iowa Supreme Court judges who overturned the state's ban on gay marriage in 2009.

Santorum, along with Minnesota Rep. Michele Bachmann and Texas Governor Rick Perry, signed the group's controversial 14-point anti-gay marriage pledge, which asks each presidential candidate to “vigorously” oppose marriage equality, be faithful to his or her own spouse, vow to protect women and children from pornography and reject Sharia law because it is a “form of totalitarian control.”

An NBC News/Marist poll shows Santorum climbing to third place in Iowa behind Mitt Romney and Ron Paul.

Vander Plaats took credit for the strong showing in a press release on Thursday.

“Eight days ago, Bob Vander Plaats, President & CEO of The FAMiLY LEADER, and Chuck Hurley, President of Iowa Family Policy Center, both personally endorsed Santorum at a press conference. They pledged to devote their time and energy to promote and support Rick Santorum as candidate for the Republican presidential nomination.”

Vander Plaats added: “Since that press conference, everywhere I go, the talk is about Santorum. The buzz I've been hearing and the pulse of the voters all indicate a come-from-behind surprise victory for Rick Santorum on January 3rd. Conservative voters are definitely beginning to coalesce around Rick Santorum.”

(Related: Rick Santorum: Bob Vander Plaats asked for money to promote endorsement.)