CNN's Alisyn Camerota asked on "New Day" about President Donald Trump's recent immigration and travel ban, which was aimed at fighting threats of radical Islam.
"Why isn't the President talking about the white terrorists who mowed down six Muslims praying at their mosque," she asked.
"I don't know," the Wisconsin Republican replied, referencing the mass shooting at a mosque in Quebec City last month
. "There's a difference."
"You don't have a group like ISIS or al Qaeda that is inspiring people around the world to take up arms and kill innocents. ... That was a one off, Alisyn," Duffy added.
Camerota mentioned 1995's Oklahoma City bombing before asking if the Trump surrogate believed that white terrorists exist. But Duffy said those incidents do not compare.
"So you give me two examples, right," Duffy replied. "If you want to compare this one person in the last 10 years that you can give an example ... Oklahoma City bombing was 20 years ago."
And "that's different than the whole movement that has taken place through ISIS, that's inspired attacks," he said.
Camerota also mentioned Dylann Roof, a white man who killed nine black Americans
in a Charleston church.
Duffy mentioned the shooting of Gabby Giffords, which was done by Jared Lee Loughner, a white American, who the lawmaker called "a leftist guy."
"And now you see violence and terror in the streets all across America, burning and beating people with Donald Trump hats," he said. "The left has to say violence is wrong."
The lawmaker asked what could be done to address terrorism from white Americans.
"How should we vet that to keep ourselves safe? I will join you in that effort, what do you do," he asked. "It's horrible. What do we do on the white supremacy front to make sure we don't have another attack like Charleston?"