Christian conservative Bob Vander Plaats on Thursday endorsed the presidential campaign of Ted Cruz.

Vander Plaats helms The Family Leader, an Iowa-based conservative group.

A two-time unsuccessful gubernatorial candidate, Vander Plaats' endorsement is highly sought in Iowa. During the two previous election cycles, he backed Iowa caucus winners Mike Huckabee in 2008 and Rick Santorum in 2012.

“Our goal is to unite conservatives around Ted Cruz,” Vander Plaats said Thursday. “We believe he'll be the nominee to take on and defeat Hillary Clinton.”

According to the latest Monmouth Poll, Cruz leads Donald Trump in Iowa by 5 percentage points.

Vander Plaats is an outspoken opponent of marriage equality and his group led the fight to unseat three Iowa Supreme Court justices over their participation in the court's unanimous 2009 ruling striking down the state's law limiting marriage to heterosexual couples.

(Related: Bob Vander Plaats proud of ousting Iowa justices over gay marriage.)

The National Organization for Marriage (NOM) also backed Cruz for president this week.