Donald Trump. Fox News/screengrab Real-estate mogul Donald Trump apparently has nothing but kind words for the supporter who asked him about anti-Muslim conspiracy theories last week.

"I think he was a hardworking guy from the area and had this on his mind," the Republican presidential front-runner reflected during a Monday interview on "Fox & Friends."

At a town-hall event last Thursday, a man told Trump that President Barack Obama was a Muslim foreigner, adding that Muslims and their training camps in the US are a "problem."

Trump stirred controversy by declining to correct the man, instead speaking vaguely about looking into many issues. Critics argue that Trump should have shown leadership by calling him out, but Trump insists he had no "moral obligation" to defend Obama.

Some observers speculated that the questioner was a "plant" to goad Trump into addressing the controversial topic, especially given his own history questioning the authenticity of Obama's birth certificate.

But Trump said on "Fox & Friends" that he thought the man was simply an earnest supporter from the neighborhood. He also noted that many of his supporters appeared to agree with the man's thoughts about Obama.

"He had a 'Trump' beautiful shirt on, which shows that he's a fan," Trump said. "When he was asking that question, by the way, a lot of the people in the audience were nodding. They were not laughing at him or anything. They were nodding."

During a Sunday interview on "Meet the Press," Trump also seemed to praise the man's passion.

"So this man got up, and he felt very strongly — whoever he was — he felt very, very strongly and very powerfully about something," Trump said then. "And whether we all agree with it or not, it wasn't my obligation to defend [Obama]."