Sarah Palin joins Donald Trump presidential campaign

Sarah Palin endorses Republican presidential candidate Donald Trump. Picture: AP

“Media heads are spinning,” Ms Palin said after taking the stage at a Trump rally at Iowa State University. “This is going to be so much fun.”

She said that, with Mr Trump as president, America would no longer apologise.

“No more pussy-footing around,” she said, adding that Mr Trump would allow the military do its job and destroy the Islamic State group.

“He’s going rogue left and right. That’s why he’s doing so well.”

Donald Trump stripped of Robert Gordon degree

“I am greatly honoured to receive Sarah’s endorsement,” Mr Trump said, announcing the support of the former Alaska governor and former running mate of Senator John McCain in his 2008 bid for the White House.

“She is a friend, and a high-quality person whom I have great respect for. I am proud to have her support.”

Mr Trump’s national political director Michael Glassner previously worked with Ms Palin, who was a virtual newcomer to the national political arena when Mr McCain named her as his running mate.

She has since risen to prominence as one of the most outspoken conservatives in the party, and signed on as a Fox News TV commentator after resigning as Alaska’s governor in 2010, a job she held until last year.

Earlier on Tuesday, Mr Trump received an endorsement from the daughter of film star John Wayne.

Standing in front of a life-size, rifle-toting model of the actor in full cowboy gear, Mr Trump accepted the endorsement of Aissa Wayne at the John Wayne Birthplace Museum in Winterset, Iowa.

“America needs help and we need a strong leader and we need someone like Mr Trump with leadership qualities, someone with courage, someone that’s strong, like John Wayne,” she said.

Sarah Palin - Attractive, earnest - and clearly out of her league?