In a competitive field, this may be Mitt Romney's worst gaffe yet. Discussing the Wisconsin shooting last night, the Republican presidential candidate twice mistakenly used the word "sheikh", denoting an Arab leader, rather than "Sikh", the religion of the victims.

Speaking at a fundraising event in West Des Moines, he said:

I was in Chicago earlier today. We had a moment of silence in honor of the people who lost their lives at that sheikh temple. I noted that it was a tragedy for many, many reasons. Among them are the fact that people, the sheikh people are among the most peaceable and loving individuals you can imagine, as is their faith.

Asked later about the slip, Romney spokesman Rick Gorka explained: "He misspoke. It was the end of the day. He mispronounced similar sounding words. He was clearly referring to the tragedy in Wisconsin. You clearly heard him talk about it earlier today in Chicago."

Fortunately for Romney, his linguistic shortcomings didn't prevent him raising $1.8m dollars in the "most successful presidential fundraiser we have ever had in the history of the state of Iowa."