Sarah Palin: I’m backing Donald Trump – he’ll kick ISIS ass

She contrasted them with conservative Republicans: “Right wingin’, bitter clingin’, proud clingers of our guns, our god, and our religions, and our Constitution.” Mr Trump said he was “greatly honoured” to receive her endorsement, adding: “She is a friend, and a high-quality person whom I have great respect for.” The businessman, currently leading the Republican field, will hope Ms Palin can boost his support in the Iowa caucus on February 1, the first contest in the race to select a presidential candidate.

Since running alongside John McCain in the 2008 election she has been a TV commentator and remains well-liked among many grassroots Republicans. Like Mr Trump she has been on reality TV and has a big social media presence, with 4.5 million Facebook followers.

It is not clear whether she has a chance of being Mr Trump running mate should he win the nomination. She has previously said she would be happy to be his energy secretary if he became president. Meanhwhile the billionaire brushed off the House of Commons debate over whether he should be banned from Britain, saying: “I am honoured by the tremendous support in the UK - by the way people have stuck up for me.”