Republican presidential candidate Donald Trump jokes that he wouldn't lose support for his campaign even if he shot people "in the middle of Fifth Avenue." (Reuters)

SIOUX CENTER, Iowa -- Donald Trump says his supporters are supremely devoted to him. But would they support him if he shot someone?

"They say I have the most loyal people -- did you ever see that? -- where I could stand in the middle of Fifth Avenue and shoot somebody, and I wouldn't lose any voters," Trump said, illustrating his point by pulling his fingers into a gun shape. "Okay? It's like incredible."

The crowd laughed and clapped, and someone in the audience shouted out love for the candidate.

"We love you, too, man," Trump said.

Trump's comment came during a campaign rally Saturday at Dordt College in northwest Iowa. The 1,500-seat theater completely filled, hundreds more watched his speech from an overflow room.

Trump devoted a chunk of his nearly 70-minute-long speech to ripping the National Review, a conservative magazine that filled its latest edition with 22 essays from conservative thought leaders who do not want Trump to become the nominee.