The phrase was an allusion to a line in a John Wayne movie that Biden had used before.

How do you explain the performance in Iowa, and why should voters believe that you can win the national election?
What happened next left her a little shaken, Moore said.
Biden said it was legitimate question, but then turned the spotlight back on her, asking: Iowas a caucus. Have you ever been to a caucus?
When she indicated yes, he rebuked her No, you havent. Youre a lying dog-faced pony soldier.
The phrase was an allusion to a line in a John Wayne movie that Biden had used before. But Moore said she was flummoxed at his reaction to what she thought was a legitimate question.
I read an article that he said [Iowa] was a punch to the gut, and Im not one to just push on wounds. Im not trying to humiliate anyone, she told The Washington Post. He wasnt sitting in at the Senate trials for impeachment, so he had Iowa to himself. And then youve been a politician for like decades how are you not way above all the other candidates?
In a statement released a few hours later, Moore wrote, I asked Joe Biden a fair question. His immediate response was to question whether I had ever attended a caucus. In my nervousness in the presence of the former Vice President, I nodded yes.
Moore has not been to a caucus, she said. But she also accused Biden of insulting her, writing in reality, it is totally irrelevant whether Ive been to a caucus or not. Joe Biden has been performing incredibly poorly in this race. His inability to answer a simple question from a nobody college student like me only exacerbates that reality.
As Biden finished answering the question, he conceded that it was a legitimate question for voters to ask.
Its not a mean question, he said. Its an honest question.